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(re)2.554 G(ad).18 E F0 -.2(bu)2.554 G .054(iltin when no v).2 F .054
(ariable names are sup-)-.25 F .742(plied as ar)72 558 R 3.243(guments. The)
-.18 F F3(typeset)3.243 E F0 -.2(bu)3.243 G .743(iltin is used to de\214ne v).2
F .743(ariables and gi)-.25 F 1.043 -.15(ve t)-.25 H .743(hem attrib).15 F .743
(utes such as)-.2 F F3 -.18(re)3.243 G(ad-).18 E(only)72 570 Q F0 5.512(.B)C
.512(ash arithmetic allo)105.022 570 R .512(ws the e)-.25 F -.25(va)-.25 G .511
(luation of an e).25 F .511(xpression and the substitution of the result.)-.15
F .511(Shell v)5.511 F(ari-)-.25 E .222
(ables may be used as operands, and the result of an e)72 582 R .222
(xpression may be assigned to a v)-.15 F 2.722(ariable. Nearly)-.25 F .222
(all of)2.722 F(the operators from the C language are a)72 594 Q -.25(va)-.2 G
(ilable, with the same precedence rules:).25 E F1 6($e)97 612 S
(cho $\(\(3 + 5 * 32\)\))115 612 Q(163)97 624 Q F0 -.15(Fo)72 645.6 S 3.24(ri)
.15 G(nteracti)91.76 645.6 Q 1.04 -.15(ve u)-.25 H .74
(se, Bash implements ksh-style aliases and b).15 F .74(uiltins such as)-.2 F F3
(fc)3.24 E F0 .74(\(discussed belo)3.24 F .74(w\) and)-.25 F F3(jobs)3.24 E F0
(.)A .291(Bash aliases allo)72 657.6 R 2.791(was)-.25 G .291
(tring to be substituted for a command name.)160.124 657.6 R(The)5.291 E 2.791
(yc)-.15 G .291(an be used to create a mnemonic)371.733 657.6 R .568(for a)72
669.6 R/F4 9/Times-Roman@0 SF(UNIX)3.068 E F0 .568(command name \()3.068 F F1
.568(alias del=rm)B F0 .568(\), to e)B .567(xpand a single w)-.15 F .567
(ord to a comple)-.1 F 3.067(xc)-.15 G .567(ommand \()432.603 669.6 R F1(alias)
A .255(news='xterm -g 80x45 -title trn -e trn -e -S1 -N &')72 681.6 R F0 .255
(\), or to ensure that a command)B(is in)72 693.6 Q -.2(vo)-.4 G -.1(ke).2 G
2.5(dw).1 G(ith a basic set of options \()122.41 693.6 Q F1
(alias ls="/bin/ls -F")A F0(\).)A .32 LW 76 703.6 72 703.6 DL 80 703.6 76 703.6
DL 84 703.6 80 703.6 DL 88 703.6 84 703.6 DL 92 703.6 88 703.6 DL 96 703.6 92
703.6 DL 100 703.6 96 703.6 DL 104 703.6 100 703.6 DL 108 703.6 104 703.6 DL
112 703.6 108 703.6 DL 116 703.6 112 703.6 DL 120 703.6 116 703.6 DL 124 703.6
120 703.6 DL 128 703.6 124 703.6 DL 132 703.6 128 703.6 DL 136 703.6 132 703.6
DL 140 703.6 136 703.6 DL 144 703.6 140 703.6 DL/F5 8/Times-Roman@0 SF
(\207Morris Bolsk)72 713.6 Q 2(ya)-.12 G(nd Da)127.88 713.6 Q(vid K)-.16 E
(orn,)-.28 E/F6 8/Times-Italic@0 SF(The K)2 E(ornShell Command and Pr)-.32 E
-.08(og)-.36 G -.12(ra).08 G(mming Langua).12 E -.08(ge)-.08 G F5 2(,P).08 G
(rentice Hall, 1989.)363.064 713.6 Q EP
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/F0 10/Times-Roman@0 SF 2.5(-3-)279.67 48 S .293(The C shell \()97 84 R/F1 10
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(yw)-.1 G .292(hile at Berk)304.534 84 R(ele)-.1 E 1.592 -.65(y, i)-.15 H 2.792
(sw).65 G .292(idely used and quite popular)389.512 84 R 1.252
(for its interacti)72 96 R 1.552 -.15(ve f)-.25 H 3.752(acilities. Bash).05 F
1.253(includes a csh-compatible history e)3.752 F 1.253(xpansion mechanism \(`)
-.15 F 1.253(`! history')-.74 F('\),)-.74 E .019(brace e)72 108 R .018
(xpansion, access to a stack of directories via the)-.15 F F1(pushd)2.518 E F0
(,)A F1(popd)2.518 E F0 2.518(,a)C(nd)357.31 108 Q F1(dirs)2.518 E F0 -.2(bu)
2.518 G .018(iltins, and tilde e).2 F(xpansion,)-.15 E 1.293
(to generate users' home directories.)72 120 R -.35(Ti)6.294 G 1.294(lde e).35
F 1.294(xpansion has also been adopted by both the K)-.15 F 1.294
(orn Shell and)-.35 F(POSIX.2.)72 132 Q .148
(There were certain areas in which POSIX.2 felt standardization w)97 147.6 R
.149(as necessary)-.1 F 2.649(,b)-.65 G .149(ut no e)420.643 147.6 R .149
(xisting imple-)-.15 F 1.598(mentation pro)72 159.6 R 1.598
(vided the proper beha)-.15 F(vior)-.2 E 6.598(.T)-.55 G 1.598(he w)251.56
159.6 R 1.597(orking group in)-.1 F -.15(ve)-.4 G 1.597
(nted and standardized functionality in).15 F .674
(these areas, which Bash implements.)72 171.6 R(The)5.674 E F1(command)3.174 E
F0 -.2(bu)3.174 G .674(iltin w).2 F .674(as in)-.1 F -.15(ve)-.4 G .674
(nted so that shell functions could be).15 F .996(written to replace b)72 183.6
R .996(uiltins; it mak)-.2 F .996(es the capabilities of the b)-.1 F .995
(uiltin a)-.2 F -.25(va)-.2 G .995(ilable to the function.).25 F .995
(The reserv)5.995 F(ed)-.15 E -.1(wo)72 195.6 S 1.566(rd `).1 F(`!')-.74 E
4.066('w)-.74 G 1.566(as added to ne)122.872 195.6 R -.05(ga)-.15 G 1.567
(te the return v).05 F 1.567(alue of a command or pipeline; it w)-.25 F 1.567
(as nearly impossible to)-.1 F -.15(ex)72 207.6 S .089(press `).15 F .089
(`if not x')-.74 F 2.589('c)-.74 G .089(leanly using the sh language.)152.366
207.6 R .089(There e)5.089 F .088
(xist multiple incompatible implementations of the)-.15 F F1(test)72 219.6 Q F0
-.2(bu)3.163 G .663(iltin, which tests \214les for type and other attrib).2 F
.664(utes and performs arithmetic and string comparisons.)-.2 F .5
(POSIX considered none of these correct, so the standard beha)72 231.6 R .5
(vior w)-.2 F .5(as speci\214ed in terms of the number of)-.1 F(ar)72 243.6 Q
.412(guments to the command.)-.18 F .412(POSIX.2 dictates e)5.412 F .412
(xactly what will happen when four or fe)-.15 F .412(wer ar)-.25 F .412
(guments are)-.18 F(gi)72 255.6 Q -.15(ve)-.25 G 5.01(nt).15 G(o)101.61 255.6 Q
F1(test)5.01 E F0 5.01(,a)C 2.51(nd lea)138.56 255.6 R -.15(ve)-.2 G 5.01(st)
.15 G 2.51(he beha)186 255.6 R 2.51(vior unde\214ned when more ar)-.2 F 2.51
(guments are supplied.)-.18 F 2.51(Bash uses the)7.51 F
(POSIX.2 algorithm, which w)72 267.6 Q(as concei)-.1 E -.15(ve)-.25 G 2.5(db)
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(3.1. F)72 291.6 R(eatur)-.25 E(es not in the Bour)-.18 E(ne Shell)-.15 E F0
.718(There are a number of minor dif)97 307.2 R .719
(ferences between Bash and the v)-.25 F .719
(ersion of sh present on most other)-.15 F -.15(ve)72 319.2 S .874(rsions of)
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(he majority of these are due to the POSIX standard, b)157.232 319.2 R .873
(ut some are the result of Bash)-.2 F .188
(adopting features from other shells.)72 331.2 R -.15(Fo)5.188 G 2.689(ri).15 G
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331.2 Q 2.689('r)-.74 G(eserv)388.153 331.2 Q .189(ed w)-.15 F .189(ord, the)
-.1 F F1(command)2.689 E F0 -.2(bu)72 343.2 S .116(iltin, the ability of the).2
F F1 -.18(re)2.616 G(ad).18 E F0 -.2(bu)2.615 G .115
(iltin to correctly return a line ending with a backslash, symbolic ar).2 F
(guments)-.18 E .798(to the)72 355.2 R F1(umask)3.298 E F0 -.2(bu)3.298 G .798
(iltin, v).2 F .798(ariable substring remo)-.25 F -.25(va)-.15 G .798(l, a w)
.25 F .799(ay to get the length of a v)-.1 F .799(ariable, and the ne)-.25 F
3.299(wa)-.25 G(lgo-)487.89 355.2 Q(rithm for the)72 367.2 Q F1(test)2.5 E F0
-.2(bu)2.5 G(iltin from the POSIX.2 standard, none of which appear in sh.).2 E
.998(Bash also implements the `)97 382.8 R(`$\(...\)')-.74 E 3.498('c)-.74 G
.998(ommand substitution syntax, which supersedes the sh `...` con-)244.93
382.8 R 2.654(struct. The)72 394.8 R -.74(``)2.654 G($\(...\)').74 E 2.654('c)
-.74 G .154(onstruct e)158.172 394.8 R .154
(xpands to the output of the command contained within the parentheses, with)
-.15 F .467(trailing ne)72 406.8 R .467(wlines remo)-.25 F -.15(ve)-.15 G 2.967
(d. The).15 F .467(sh syntax is accepted for backw)2.967 F .467
(ards compatibility)-.1 F 2.966(,b)-.65 G .466(ut the `)415.026 406.8 R
(`$\(...\)')-.74 E 2.966('f)-.74 G .466(orm is)478.254 406.8 R(preferred becau\
se its quoting rules are much simpler and it is easier to nest.)72 418.8 Q .772
(The Bourne shell does not pro)97 434.4 R .772(vide such features as brace e)
-.15 F .772(xpansion, the ability to de\214ne a v)-.15 F(ariable)-.25 E .283
(and a function with the same name, local v)72 446.4 R .282
(ariables in shell functions, the ability to enable and disable indi-)-.25 F
.547(vidual b)72 458.4 R .547(uiltins or write a function to replace a b)-.2 F
.547(uiltin, or a means to e)-.2 F .547(xport a shell function to a child pro-)
-.15 F(cess.)72 470.4 Q .32
(Bash has closed a long-standing shell security hole by not using the)97 486 R
F1($IFS)2.82 E F0 -.25(va)2.82 G .32(riable to split each w).25 F(ord)-.1 E
1.254(read by the shell, b)72 498 R 1.254(ut splitting only the results of e)
-.2 F 1.255(xpansion \(ksh and the 4.4 BSD sh ha)-.15 F 1.555 -.15(ve \214)-.2
H -.15(xe).15 G 3.755(dt).15 G 1.255(his as)480.245 498 R 2.752(well\). Useful)
72 510 R(beha)2.751 E .251(vior such as a means to abort e)-.2 F -.15(xe)-.15 G
.251(cution of a script read with the `).15 F(`.)-.74 E 1.731 -.74('' c)-.7 H
.251(ommand using the).74 F F1 -.18(re)72 522 S(tur).18 E(n)-.15 E F0 -.2(bu)
2.742 G .242(iltin or automatically e).2 F .242(xporting v)-.15 F .243
(ariables in the shell')-.25 F 2.743(se)-.55 G -.4(nv)336.842 522 S .243
(ironment to children is also not present).4 F .969(in the Bourne shell.)72 534
R .968(Bash pro)5.968 F .968(vides a much more po)-.15 F .968(werful en)-.25 F
.968(vironment for both interacti)-.4 F 1.268 -.15(ve u)-.25 H .968
(se and pro-).15 F(gramming.)72 546 Q F1 2.5(4. Bash-speci\214c)72 570 R -.25
(Fe)2.5 G(atur).25 E(es)-.18 E F0 .491(This section details a fe)97 585.6 R
2.991(wo)-.25 G 2.991(ft)208.355 585.6 S .491(he features which mak)217.456
585.6 R 2.991(eB)-.1 G .491(ash unique.)323.18 585.6 R .492(Most of them pro)
5.491 F .492(vide impro)-.15 F -.15(ve)-.15 G(d).15 E(interacti)72 597.6 Q
1.182 -.15(ve u)-.25 H .882(se, b).15 F .882(ut a fe)-.2 F 3.382(wp)-.25 G .882
(rogramming impro)183.31 597.6 R -.15(ve)-.15 G .882
(ments are present as well.).15 F .882(Full descriptions of these fea-)5.882 F
(tures can be found in the Bash documentation.)72 609.6 Q F1 2.5(4.1. Startup)
72 633.6 R(Files)2.5 E F0 .161(Bash e)97 649.2 R -.15(xe)-.15 G .161
(cutes startup \214les dif).15 F .161(ferently than other shells.)-.25 F .162
(The Bash beha)5.161 F .162(vior is a compromise between)-.2 F .116
(the csh principle of startup \214les with \214x)72 661.2 R .116(ed names e)
-.15 F -.15(xe)-.15 G .116(cuted for each shell and the sh `).15 F
(`minimalist')-.74 E 2.615('b)-.74 G(eha)472.26 661.2 Q(vior)-.2 E(.)-.55 E
2.844(An interacti)72 673.2 R 3.144 -.15(ve i)-.25 H 2.844
(nstance of Bash started as a login shell reads and e).15 F -.15(xe)-.15 G
(cutes).15 E/F3 10/Times-Italic@0 SF(~/.bash_pr)5.345 E(o\214le)-.45 E F0 2.845
(\(the \214le)7.011 F .954(.bash_pro\214le in the user')72 685.2 R 3.454(sh)
-.55 G .953(ome directory\), if it e)186.086 685.2 R 3.453(xists. An)-.15 F
(interacti)3.453 E 1.253 -.15(ve n)-.25 H .953(on-login shell reads and e).15 F
-.15(xe)-.15 G(cutes).15 E .32 LW 76 695.2 72 695.2 DL 80 695.2 76 695.2 DL 84
695.2 80 695.2 DL 88 695.2 84 695.2 DL 92 695.2 88 695.2 DL 96 695.2 92 695.2
DL 100 695.2 96 695.2 DL 104 695.2 100 695.2 DL 108 695.2 104 695.2 DL 112
695.2 108 695.2 DL 116 695.2 112 695.2 DL 120 695.2 116 695.2 DL 124 695.2 120
695.2 DL 128 695.2 124 695.2 DL 132 695.2 128 695.2 DL 136 695.2 132 695.2 DL
140 695.2 136 695.2 DL 144 695.2 140 695.2 DL/F4 8/Times-Roman@0 SF .764
(\207Bill Jo)72 705.2 R 1.804 -.52(y, A)-.08 H 2.764(nI).52 G .764
(ntroduction to the C Shell,)121.252 705.2 R/F5 8/Times-Italic@0 SF .763
(UNIX User')2.764 F 2.763(sS)-.32 G .763(upplementary Documents)260.942 705.2 R
F4 2.763(,U)C(ni)354.228 705.2 Q -.12(ve)-.2 G .763
(rsity of California at Berk).12 F(ele)-.08 E -.52(y,)-.12 G(1986.)72 715.2 Q
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/F0 10/Times-Roman@0 SF 2.5(-4-)279.67 48 S/F1 10/Times-Italic@0 SF(~/.bashr)72
84 Q(c)-.37 E F0 5.537(.A)1.666 G(non-interacti)127.42 84 Q .837 -.15(ve s)-.25
H .537(hell \(one be).15 F .538(gun to e)-.15 F -.15(xe)-.15 G .538
(cute a shell script, for e).15 F .538(xample\) reads no \214x)-.15 F .538
(ed startup)-.15 F .342(\214le, b)72 96 R .342(ut uses the v)-.2 F .342
(alue of the v)-.25 F(ariable)-.25 E/F2 10/Times-Bold@0 SF($ENV)2.842 E F0
2.841(,i)C 2.841(fs)260.187 96 S .341(et, as the name of a startup \214le.)
270.248 96 R .341(The ksh practice of read-)5.341 F(ing)72 108 Q F2($ENV)3.114
E F0 .614(for e)3.114 F -.15(ve)-.25 G .614(ry shell, with the accompan).15 F
.615(ying dif)-.15 F .615(\214culty of de\214ning the proper v)-.25 F .615
(ariables and functions)-.25 F .721(for interacti)72 120 R 1.021 -.15(ve a)-.25
H .721(nd non-interacti).15 F 1.021 -.15(ve s)-.25 H .721(hells or ha).15 F
.721(ving the \214le read only for interacti)-.2 F 1.02 -.15(ve s)-.25 H .72
(hells, w).15 F .72(as considered)-.1 F .158(too comple)72 132 R 2.658(x. Ease)
-.15 F .158(of use w)2.658 F .158(on out here.)-.1 F(Interestingly)5.158 E
2.658(,t)-.65 G .158(he ne)295.822 132 R .159
(xt release of ksh will change to reading)-.15 F F2($ENV)2.659 E F0
(only for interacti)72 144 Q .3 -.15(ve s)-.25 H(hells.).15 E F2 2.5(4.2. New)
72 168 R(Builtin Commands)2.5 E F0 1.02(There are a fe)97 183.6 R 3.52(wb)-.25
G 1.02(uiltins which are ne)170.59 183.6 R 3.52(wo)-.25 G 3.52(rh)267.74 183.6
S -2.25 -.2(av e)279.59 183.6 T 1.02(been e)3.72 F 1.02(xtended in Bash.)-.15 F
(The)6.02 E F2(enable)3.52 E F0 -.2(bu)3.52 G 1.02(iltin allo).2 F(ws)-.25 E
-.2(bu)72 195.6 S .736(iltin commands to be turned on and of).2 F 3.236(fa)-.25
G(rbitrarily)250.198 195.6 Q 5.736(.T)-.65 G 3.237(ou)298.644 195.6 S .737
(se the v)311.881 195.6 R .737(ersion of)-.15 F F1(ec)3.237 E(ho)-.15 E F0 .737
(found in a user')4.903 F 3.237(ss)-.55 G(earch)482.35 195.6 Q .625
(path rather than the Bash b)72 207.6 R(uiltin,)-.2 E/F3 10/Courier@0 SF .625
(enable -n echo)3.125 F F0(suf)3.125 E 3.125(\214ces. The)-.25 F F2(help)3.124
E F0 -.2(bu)3.124 G .624(iltin pro).2 F .624(vides quick synopses)-.15 F .703
(of the shell f)72 219.6 R .704
(acilities without requiring access to a manual page.)-.1 F F2(Builtin)5.704 E
F0 .704(is similar to)3.204 F F2(command)3.204 E F0 .704(in that it)3.204 F
.342(bypasses shell functions and directly e)72 231.6 R -.15(xe)-.15 G .342
(cutes b).15 F .342(uiltin commands.)-.2 F .342
(Access to a csh-style stack of directories)5.342 F .072(is pro)72 243.6 R .073
(vided via the)-.15 F F2(pushd)2.573 E F0(,)A F2(popd)2.573 E F0 2.573(,a)C(nd)
211.197 243.6 Q F2(dirs)2.573 E F0 -.2(bu)2.573 G(iltins.).2 E F2(Pushd)5.073 E
F0(and)2.573 E F2(popd)2.573 E F0 .073(insert and remo)2.573 F .373 -.15(ve d)
-.15 H .073(irectories from the).15 F 2.858(stack, respecti)72 255.6 R -.15(ve)
-.25 G(ly).15 E 5.358(,a)-.65 G(nd)159.976 255.6 Q F2(dirs)5.358 E F0 2.858
(lists the stack contents.)5.358 F 2.858(On systems that allo)7.858 F 5.358
<778c>-.25 G 2.857(ne-grained control of)413.866 255.6 R 1.339(resources, the)
72 267.6 R F2(ulimit)3.839 E F0 -.2(bu)3.839 G 1.339
(iltin can be used to tune these settings.).2 F F2(Ulimit)6.34 E F0(allo)3.84 E
1.34(ws a user to control, among)-.25 F 1.086
(other things, whether core dumps are to be generated, ho)72 279.6 R 3.586(wm)
-.25 G 1.086(uch memory the shell or a child process is)327.002 279.6 R(allo)72
291.6 Q .496(wed to allocate, and ho)-.25 F 2.996(wl)-.25 G(ar)193.96 291.6 Q
.496(ge a \214le created by a child process can gro)-.18 F 4.296 -.65(w. T)-.25
H(he).65 E F2(suspend)2.996 E F0 .497(command will)2.997 F .744
(stop the shell process when job control is acti)72 303.6 R -.15(ve)-.25 G
3.243(;m).15 G .743(ost other shells do not allo)282.443 303.6 R 3.243(wt)-.25
G(hemselv)404.431 303.6 Q .743(es to be stopped)-.15 F(lik)72 315.6 Q 2.717(et)
-.1 G(hat.)92.397 315.6 Q F2 -.74(Ty)5.217 G(pe,).74 E F0 .217
(the Bash answer to)2.717 F F2(which)2.717 E F0(and)2.717 E F2(whence,)2.717 E
F0(sho)2.717 E .218(ws what will happen when a w)-.25 F .218(ord is typed as a)
-.1 F(command:)72 327.6 Q F3 6($t)97 345.6 S(ype export)115 345.6 Q
(export is a shell builtin)97 357.6 Q 6($t)97 369.6 S(ype -t export)115 369.6 Q
(builtin)97 381.6 Q 6($t)97 393.6 S(ype bash)115 393.6 Q(bash is /bin/bash)97
405.6 Q 6($t)97 417.6 S(ype cd)115 417.6 Q(cd is a function)97 429.6 Q(cd \(\))
97 441.6 Q({)97 453.6 Q(builtin cd ${1+"$@"} && xtitle $HOST: $PWD)121 465.6 Q
(})97 477.6 Q F0 -1.11(Va)72 499.2 S .682(rious modes tell what a command w)
1.11 F .681(ord is \(reserv)-.1 F .681(ed w)-.15 F .681
(ord, alias, function, b)-.1 F .681(uiltin, or \214le\) or which v)-.2 F(er)
-.15 E(-)-.2 E 1.15(sion of a command will be e)72 511.2 R -.15(xe)-.15 G 1.15
(cuted based on a user').15 F 3.65(ss)-.55 G 1.15(earch path.)305.7 511.2 R
1.15(Some of this functionality has been)6.15 F
(adopted by POSIX.2 and folded into the)72 523.2 Q F2(command)2.5 E F0(utility)
2.5 E(.)-.65 E F2 2.5(4.3. Editing)72 547.2 R(and Completion)2.5 E F0 .584
(One area in which Bash shines is command line editing.)97 562.8 R .584
(Bash uses the)5.584 F F1 -.37(re)3.084 G(adline).37 E F0 .583
(library to read and)4.749 F .942(edit lines when interacti)72 574.8 R -.15(ve)
-.25 G 5.942(.R).15 G .942(eadline is a po)194.798 574.8 R .942
(werful and \215e)-.25 F .942(xible input f)-.15 F .943
(acility that a user can con\214gure to)-.1 F(indi)72 586.8 Q .732
(vidual tastes.)-.25 F .732(It allo)5.732 F .732
(ws lines to be edited using either emacs or vi commands, where those commands)
-.25 F .2(are appropriate.)72 598.8 R .2
(The full capability of emacs is not present \255 there is no w)5.2 F .2
(ay to e)-.1 F -.15(xe)-.15 G .2(cute a named command).15 F 1.15
(with M-x, for instance \255 b)72 610.8 R 1.15(ut the e)-.2 F 1.149
(xisting commands are more than adequate.)-.15 F 1.149
(The vi mode is compliant)6.149 F
(with the command line editing standardized by POSIX.2.)72 622.8 Q 1.69
(Readline is fully customizable.)97 638.4 R 1.691
(In addition to the basic commands and k)6.69 F 1.991 -.15(ey b)-.1 H 1.691
(indings, the library).15 F(allo)72 650.4 Q .83
(ws users to de\214ne additional k)-.25 F 1.13 -.15(ey b)-.1 H .83
(indings using a startup \214le.).15 F(The)5.83 E F1(inputr)3.329 E(c)-.37 E F0
.829(\214le, which def)4.995 F .829(aults to the)-.1 F(\214le)72 662.4 Q F1
(~/.inputr)4.287 E(c)-.37 E F0 4.287(,i)1.666 G 4.287(sr)137.43 662.4 S 1.788(\
ead each time readline initializes, permitting users to maintain a consistent \
interf)148.937 662.4 R(ace)-.1 E .547(across a set of programs.)72 674.4 R .546
(Readline includes an e)5.546 F .546(xtensible interf)-.15 F .546
(ace, so each program using the library can)-.1 F .23(add its o)72 686.4 R .23
(wn bindable commands and program-speci\214c k)-.25 F .531 -.15(ey b)-.1 H
2.731(indings. Bash).15 F .231(uses this f)2.731 F .231
(acility to add bindings)-.1 F(that perform history e)72 698.4 Q
(xpansion or shell w)-.15 E(ord e)-.1 E(xpansions on the current input line.)
-.15 E .707(Readline interprets a number of v)97 714 R .706
(ariables which further tune its beha)-.25 F(vior)-.2 E 5.706(.V)-.55 G .706
(ariables e)408.432 714 R .706(xist to control)-.15 F .157
(whether or not eight-bit characters are directly read as input or con)72 726 R
-.15(ve)-.4 G .158(rted to meta-pre\214x).15 F .158(ed k)-.15 F .458 -.15(ey s)
-.1 H .158(equences \(a).15 F EP
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/F0 10/Times-Roman@0 SF 2.5(-5-)279.67 48 S(meta-pre\214x)72 84 Q 1.575(ed k)
-.15 F 1.875 -.15(ey s)-.1 H 1.575
(equence consists of the character with the eighth bit zeroed, preceded by the)
.15 F/F1 10/Times-Italic@0 SF(meta-)4.074 E(pr)72 96 Q(e\214x)-.37 E F0
(character)4.45 E 2.784(,u)-.4 G .284
(sually escape, which selects an alternate k)145.374 96 R -.15(ey)-.1 G .285
(map\), to decide whether to output characters).15 F .485
(with the eighth bit set directly or as a meta-pre\214x)72 108 R .485(ed k)-.15
F .784 -.15(ey s)-.1 H .484(equence, whether or not to wrap to a ne).15 F 2.984
(ws)-.25 G(creen)482.35 108 Q .157
(line when a line being edited is longer than the screen width, the k)72 120 R
-.15(ey)-.1 G .158(map to which subsequent k).15 F .458 -.15(ey b)-.1 H
(indings).15 E .531(should apply)72 132 R 3.031(,o)-.65 G 3.031(re)133.802 132
S -.15(ve)144.353 132 S 3.031(nw).15 G .531(hat happens when readline w)168.894
132 R .531(ants to ring the terminal')-.1 F 3.03(sb)-.55 G 3.03(ell. All)399.37
132 R .53(of these v)3.03 F(ariables)-.25 E(can be set in the inputrc \214le.)
72 144 Q .284(The startup \214le understands a set of C preprocessor)97 159.6 R
(-lik)-.2 E 2.785(ec)-.1 G .285(onditional constructs which allo)329.49 159.6 R
2.785(wv)-.25 G(ariables)472.9 159.6 Q .12(or k)72 171.6 R .42 -.15(ey b)-.1 H
.119(indings to be assigned based on the application using readline, the termi\
nal currently being used, or).15 F .338(the editing mode.)72 183.6 R .338
(Users can add program-speci\214c bindings to mak)5.338 F 2.838(et)-.1 G .338
(heir li)353.02 183.6 R -.15(ve)-.25 G 2.838(se).15 G 2.838(asier: I)397.176
183.6 R(ha)2.838 E .639 -.15(ve b)-.2 H .339(indings that).15 F
(let me edit the v)72 195.6 Q(alue of)-.25 E/F2 10/Times-Bold@0 SF($P)2.5 E
-.95(AT)-.74 G(H).95 E F0(and double-quote the current or pre)2.5 E(vious w)
-.25 E(ord:)-.1 E/F3 10/Courier@0 SF 6(#M)97 213.6 S
(acros that are convenient for shell interaction)115 213.6 Q($if Bash)97 225.6
Q 6(#e)97 237.6 S(dit the path)115 237.6 Q
("\\C-xp": "PATH=${PATH}\\e\\C-e\\C-a\\ef\\C-f")97 249.6 Q 6(#p)97 261.6 S
(repare to type a quoted word -- insert open and close double)115 261.6 Q 6(#q)
97 273.6 S(uotes and move to just after the open quote)115 273.6 Q
("\\C-x\\"": "\\"\\"\\C-b")97 285.6 Q 6(#Q)97 297.6 S
(uote the current or previous word)115 297.6 Q("\\C-xq": "\\eb\\"\\ef\\"")97
309.6 Q($endif)97 321.6 Q F0 .322(There is a readline command to re-read the \
\214le, so users can edit the \214le, change some bindings, and be)72 343.2 R
(gin)-.15 E(to use them almost immediately)72 355.2 Q(.)-.65 E .851
(Bash implements the)97 370.8 R F2(bind)3.351 E F0 -.2(bu)3.351 G .851
(iltin for more dyamic control of readline than the startup \214le permits.).2
F F2(Bind)72 382.8 Q F0 .167(is used in se)2.667 F -.15(ve)-.25 G .167(ral w)
.15 F 2.667(ays. In)-.1 F F1(list)2.667 E F0 .167
(mode, it can display the current k)4.333 F .466 -.15(ey b)-.1 H .166
(indings, list all the readline edit-).15 F .149(ing directi)72 394.8 R -.15
(ve)-.25 G 2.649(sa).15 G -.25(va)132.798 394.8 S .149
(ilable for binding, list which k).25 F -.15(ey)-.1 G 2.649(si).15 G -1.9 -.4
(nv o)282.352 394.8 T .349 -.1(ke a g).4 H -2.15 -.25(iv e).1 H 2.65(nd).25 G
(irecti)345.3 394.8 Q -.15(ve)-.25 G 2.65(,o).15 G 2.65(ro)385.04 394.8 S .15
(utput the current set of k)396.02 394.8 R -.15(ey)-.1 G .526(bindings in a fo\
rmat that can be incorporated directly into an inputrc \214le.)72 406.8 R(In)
5.526 E F1(batc)3.026 E(h)-.15 E F0 .526(mode, it reads a series)4.692 F .71
(of k)72 418.8 R 1.01 -.15(ey b)-.1 H .71
(indings directly from a \214le and passes them to readline.).15 F .71
(In its most common usage,)5.71 F F2(bind)3.21 E F0(tak)3.21 E .71(es a)-.1 F
.534(single string and passes it directly to readline, which interprets the li\
ne as if it had just been read from the)72 430.8 R(inputrc \214le.)72 442.8 Q
(Both k)5 E .3 -.15(ey b)-.1 H(indings and v).15 E
(ariable assignments may appear in the string gi)-.25 E -.15(ve)-.25 G 2.5(nt)
.15 G(o)427.74 442.8 Q F2(bind)2.5 E F0(.)A .401(The readline library also pro)
97 458.4 R .402(vides an interf)-.15 F .402(ace for)-.1 F F1(wor)2.902 E 2.902
(dc)-.37 G(ompletion)328.546 458.4 Q F0 5.402(.W)C .402(hen the)385.888 458.4 R
F1(completion)2.902 E F0(character)4.568 E 1.261(\(usually T)72 470.4 R 1.261
(AB\) is typed, readline looks at the w)-.93 F 1.26
(ord currently being entered and computes the set of \214le-)-.1 F .523
(names of which the current w)72 482.4 R .523(ord is a v)-.1 F .523
(alid pre\214x.)-.25 F .524
(If there is only one possible completion, the rest of the)5.523 F .358
(characters are inserted directly)72 494.4 R 2.858(,o)-.65 G .358(therwise the\
 common pre\214x of the set of \214lenames is added to the current)205.232
494.4 R -.1(wo)72 506.4 S 3.199(rd. A).1 F .699(second T)3.199 F .699(AB chara\
cter entered immediately after a non-unique completion causes readline to list)
-.93 F 1.814(the possible completions; there is an option to ha)72 518.4 R
2.113 -.15(ve t)-.2 H 1.813(he list displayed immediately).15 F 6.813(.R)-.65 G
1.813(eadline pro)436.517 518.4 R(vides)-.15 E .482
(hooks so that applications can pro)72 530.4 R .482
(vide speci\214c types of completion before the def)-.15 F .483
(ault \214lename completion)-.1 F .132(is attempted.)72 542.4 R .132
(This is quite \215e)5.132 F .132(xible, though it is not completely user)-.15
F 2.632(-programmable. Bash,)-.2 F .132(for e)2.632 F .132(xample, can)-.15 F
.37(complete \214lenames, command names \(including aliases, b)72 554.4 R .37
(uiltins, shell reserv)-.2 F .37(ed w)-.15 F .37(ords, shell functions, and)-.1
F -.15(exe)72 566.4 S .424(cutables found in the \214le system\), shell v).15 F
.424(ariables, usernames, and hostnames.)-.25 F .423
(It uses a set of heuristics)5.424 F(that, while not perfect, is generally qui\
te good at determining what type of completion to attempt.)72 578.4 Q F2 2.5
(4.4. History)72 602.4 R F0 .144(Access to the list of commands pre)97 618 R
.144(viously entered \(the)-.25 F F1 .144(command history)2.644 F F0 2.644(\)i)
C 2.644(sp)398.014 618 S(ro)409.548 618 Q .144(vided jointly by Bash)-.15 F
.078(and the readline library)72 630 R 5.077(.B)-.65 G .077(ash pro)178.861 630
R .077(vides v)-.15 F .077(ariables \()-.25 F F2($HISTFILE)A F0(,)A F2
($HISTSIZE)2.577 E F0 2.577(,a)C(nd)391.916 630 Q F2($HISTCONTR)2.577 E(OL)-.3
E F0 2.577(\)a)C(nd)494 630 Q(the)72 642 Q F2(history)2.89 E F0(and)2.89 E F2
(fc)2.89 E F0 -.2(bu)2.89 G .39(iltins to manipulate the history list.).2 F
.391(The v)5.391 F .391(alue of)-.25 F F2($HISTFILE)2.891 E F0 .391
(specifes the \214le where)2.891 F .49(Bash writes the command history on e)72
654 R .489(xit and reads it on startup.)-.15 F F2($HISTSIZE)5.489 E F0 .489
(is used to limit the number)2.989 F .642(of commands sa)72 666 R -.15(ve)-.2 G
3.142(di).15 G 3.142(nt)158.286 666 S .642(he history)169.208 666 R(.)-.65 E F2
($HISTCONTR)5.642 E(OL)-.3 E F0(pro)3.142 E .642
(vides a crude form of control o)-.15 F -.15(ve)-.15 G 3.142(rw).15 G .642
(hich com-)463.088 666 R .32(mands are sa)72 678 R -.15(ve)-.2 G 2.819(do).15 G
2.819(nt)146.199 678 S .319(he history list: a v)156.798 678 R .319(alue of)
-.25 F F1(ignor)2.819 E(espace)-.37 E F0 .319(means to not sa)4.485 F .619 -.15
(ve c)-.2 H .319(ommands which be).15 F .319(gin with)-.15 F 2.866(as)72 690 S
.366(pace; a v)83.196 690 R .366(alue of)-.25 F F1(ignor)2.866 E(edups)-.37 E
F0 .367(means to not sa)4.533 F .667 -.15(ve c)-.2 H .367
(ommands identical to the last command sa).15 F -.15(ve)-.2 G(d.).15 E F2
($HIST)5.367 E(-)-.92 E(CONTR)72 702 Q(OL)-.3 E F0 -.1(wa)3.778 G 3.778(sn).1 G
(amed)150.266 702 Q F2($history_contr)3.778 E(ol)-.18 E F0 1.278(in earlier v)
3.778 F 1.278(ersions of Bash; the old name is still accepted for)-.15 F(backw)
72 714 Q .575(ards compatibility)-.1 F 5.575(.T)-.65 G(he)184.61 714 Q F2
(history)3.075 E F0 .575
(command can read or write \214les containing the history list and dis-)3.075 F
.167(play the current list contents.)72 726 R(The)5.167 E F2(fc)2.667 E F0 -.2
(bu)2.667 G .167(iltin, adopted from POSIX.2 and the K).2 F .167
(orn Shell, allo)-.35 F .167(ws display and)-.25 F EP
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/F0 10/Times-Roman@0 SF 2.5(-6-)279.67 48 S(re-e)72 84 Q -.15(xe)-.15 G .58
(cution, with optional editing, of commands from the history list.).15 F .58
(The readline library of)5.58 F .58(fers a set of)-.25 F 1.255(commands to sea\
rch the history list for a portion of the current input line or a string typed\
 by the user)72 96 R(.)-.55 E(Finally)72 108 Q 3.499(,t)-.65 G(he)108.469 108 Q
/F1 10/Times-Italic@0 SF(history)3.499 E F0(library)5.165 E 3.499(,g)-.65 G 1
(enerally incorporated directly into the readline library)191.362 108 R 3.5(,i)
-.65 G 1(mplements a f)420.44 108 R(acility)-.1 E .613(for history recall, e)72
120 R .613(xpansion, and re-e)-.15 F -.15(xe)-.15 G .613(cution of pre).15 F
.613(vious commands v)-.25 F .613(ery similar to csh \(`)-.15 F .612
(`bang history')-.74 F(',)-.74 E(so called because the e)72 132 Q
(xclamation point introduces a history substitution\):)-.15 E/F2 10/Courier@0
SF 6($e)97 150 S(cho a b c d e)115 150 Q 6(abcde)97 162 S 6($!)97 174 S 6
(!fghi)115 174 S(echo a b c d e f g h i)97 186 Q 6(abcdefghi)97 198 S 6($!)97
210 S(-2)115 210 Q(echo a b c d e)97 222 Q 6(abcde)97 234 S 6($e)97 246 S
(cho !-2:1-4)115 246 Q(echo a b c d)97 258 Q 6(abcd)97 270 S F0 1.456
(The command history is only sa)72 291.6 R -.15(ve)-.2 G 3.957(dw).15 G 1.457
(hen the shell is interacti)232.599 291.6 R -.15(ve)-.25 G 3.957(,s).15 G 3.957
(oi)352.804 291.6 S 3.957(ti)364.541 291.6 S 3.957(sn)374.058 291.6 S 1.457
(ot a)386.905 291.6 R -.25(va)-.2 G 1.457(ilable for use by shell).25 F
(scripts.)72 303.6 Q/F3 10/Times-Bold@0 SF 2.5(4.5. New)72 327.6 R(Shell V)2.5
E(ariables)-.92 E F0 .59(There are a number of con)97 343.2 R -.15(ve)-.4 G
.589(nience v).15 F .589(ariables that Bash interprets to mak)-.25 F 3.089(el)
-.1 G .589(ife easier)403.093 343.2 R 5.589(.T)-.55 G .589(hese include)453.701
343.2 R F3(FIGNORE)72 355.2 Q F0 3.973(,w)C 1.473
(hich is a set of \214lename suf)132.363 355.2 R<8c78>-.25 E 1.474
(es identifying \214les to e)-.15 F 1.474(xclude when completing \214lenames;)
-.15 F F3(HOSTTYPE)72 367.2 Q F0 2.932(,w)C .432
(hich is automatically set to a string describing the type of hardw)139.112
367.2 R .431(are on which Bash is cur)-.1 F(-)-.2 E .335(rently e)72 379.2 R
-.15(xe)-.15 G(cuting;).15 E F3(command_oriented_history)2.835 E F0 2.835(,w)C
.335(hich directs Bash to sa)272.685 379.2 R .635 -.15(ve a)-.2 H .336
(ll lines of a multiple-line com-).15 F 1.071(mand such as a)72 391.2 R F1
(while)3.571 E F0(or)3.571 E F1(for)3.571 E F0 1.071
(loop in a single history entry)3.571 F 3.57(,a)-.65 G(llo)321.92 391.2 Q 1.07
(wing easy re-editing; and)-.25 F F3(IGNOREEOF)3.57 E F0(,)A .747(whose v)72
403.2 R .747(alue indicates the number of consecuti)-.25 F 1.047 -.15(ve E)-.25
H .747(OF characters that an interacti).15 F 1.048 -.15(ve s)-.25 H .748
(hell will read before).15 F -.15(ex)72 415.2 S 1.432(iting \255 an easy w).15
F 1.432(ay to k)-.1 F 1.432(eep yourself from being logged out accidentally)-.1
F 6.432(.T)-.65 G(he)399.926 415.2 Q F3(auto_r)3.932 E(esume)-.18 E F0 -.25(va)
3.932 G(riable).25 E .571(alters the w)72 427.2 R .571
(ay the shell treats simple command names: if job control is acti)-.1 F -.15
(ve)-.25 G 3.071(,a).15 G .571(nd this v)396.954 427.2 R .571
(ariable is set, sin-)-.25 F(gle-w)72 439.2 Q .239(ord simple commands without\
 redirections cause the shell to \214rst look for and restart a suspended job)
-.1 F(with that name before starting a ne)72 451.2 Q 2.5(wp)-.25 G(rocess.)
225.33 451.2 Q F3 2.5(4.6. Brace)72 475.2 R(Expansion)2.5 E F0 .653
(Since sh of)97 490.8 R .653(fers no con)-.25 F -.15(ve)-.4 G .653(nient w).15
F .653(ay to generate arbitrary strings that share a common pre\214x or suf)-.1
F<8c78>-.25 E 2.124(\(\214lename e)72 502.8 R 2.124
(xpansion requires that the \214lenames e)-.15 F 2.123(xist\), Bash implements)
-.15 F F1(br)4.623 E 2.123(ace e)-.15 F(xpansion)-.2 E F0 4.623(,ac)C
(apability)469 502.8 Q(pick)72 514.8 Q .773(ed up from csh.)-.1 F .774(Brace e)
5.773 F .774(xpansion is similar to \214lename e)-.15 F .774(xpansion, b)-.15 F
.774(ut the strings generated need not)-.2 F 1.107(correspond to e)72 526.8 R
1.107(xisting \214les.)-.15 F 3.607(Ab)6.107 G 1.107(race e)207.655 526.8 R
1.107(xpression consists of an optional)-.15 F F1(pr)3.606 E(eamble)-.37 E F0
3.606(,f)1.666 G(ollo)419.286 526.8 Q 1.106(wed by a pair of)-.25 F 2.809
(braces enclosing a series of comma-separated strings, and an optional)72 538.8
R F1(postamble)5.31 E F0 7.81(.T)1.666 G 2.81(he preamble is)440.06 538.8 R(pr\
epended to each string within the braces, and the postamble is then appended t\
o each resulting string:)72 550.8 Q F2 6($e)97 568.8 S(cho a{d,c,b}e)115 568.8
Q(ade ace abe)97 580.8 Q F0 .306(As this e)72 602.4 R .306
(xample demonstrates, the results of brace e)-.15 F .305
(xpansion are not sorted, as the)-.15 F 2.805(ya)-.15 G .305
(re by \214lename e)416.315 602.4 R(xpan-)-.15 E(sion.)72 614.4 Q F3 2.5
(4.7. Pr)72 638.4 R(ocess Substitution)-.18 E F0 .457
(On systems that can support it, Bash pro)97 654 R .457(vides a f)-.15 F .457
(acility kno)-.1 F .458(wn as)-.25 F F1(pr)2.958 E .458(ocess substitution)-.45
F F0 5.458(.P)C .458(rocess sub-)458.832 654 R .347(stitution is similar to co\
mmand substitution in that its speci\214cation includes a command to e)72 666 R
-.15(xe)-.15 G .346(cute, b).15 F .346(ut the)-.2 F .181
(shell does not collect the command')72 678 R 2.681(so)-.55 G .181
(utput and insert it into the command line.)228.076 678 R(Rather)5.181 E 2.681
(,B)-.4 G .182(ash opens a pipe)437.635 678 R 1.763
(to the command, which is run in the background.)72 690 R 1.763
(The shell uses named pipes \(FIFOs\) or the)6.763 F F1(/de)4.263 E(v/fd)-.15 E
F0 .961(method of naming open \214les to e)72 702 R .962
(xpand the process substitution to a \214lename which connects to the pipe)-.15
F .104(when opened.)72 714 R .103(This \214lename becomes the result of the e)
5.104 F 2.603(xpansion. Process)-.15 F .103(substitution can be used to com-)
2.603 F(pare the outputs of tw)72 726 Q 2.5(od)-.1 G(if)171.61 726 Q(ferent v)
-.25 E(ersions of an application as part of a re)-.15 E(gression test:)-.15 E
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/F0 10/Times-Roman@0 SF 2.5(-7-)279.67 48 S/F1 10/Courier@0 SF 6($c)97 84 S
(mp <\(old_prog\) <\(new_prog\))115 84 Q/F2 10/Times-Bold@0 SF 2.5(4.8. Pr)72
114 R(ompt Customization)-.18 E F0 2.229(One of the more popular interacti)97
129.6 R 2.529 -.15(ve f)-.25 H 2.229(eatures that Bash pro).15 F 2.23
(vides is the ability to customize the)-.15 F 3.234(prompt. Both)72 141.6 R F2
($PS1)3.234 E F0(and)3.234 E F2($PS2,)3.234 E F0 .734
(the primary and secondary prompts, are e)3.234 F .733
(xpanded before being displayed.)-.15 F -.15(Pa)72 153.6 S .804(rameter and v)
.15 F .804(ariable e)-.25 F .805
(xpansion is performed when the prompt string is e)-.15 F .805(xpanded, so an)
-.15 F 3.305(ys)-.15 G .805(hell v)453.735 153.6 R(ariable)-.25 E .729
(can be put into the prompt \(e.g.,)72 165.6 R F2($SHL)3.228 E(VL)-.92 E F0
3.228(,w)C .728(hich indicates ho)258.568 165.6 R 3.228(wd)-.25 G .728
(eeply the current shell is nested\).)342.992 165.6 R(Bash)5.728 E 1.895
(specially interprets characters in the prompt string preceded by a backslash.)
72 177.6 R 1.895(Some of these backslash)6.895 F .874
(escapes are replaced with the current time, the date, the current w)72 189.6 R
.874(orking directory)-.1 F 3.373(,t)-.65 G .873(he username, and the)416.961
189.6 R .78(command number or history number of the command being entered.)72
201.6 R .781(There is e)5.781 F -.15(ve)-.25 G 3.281(nab).15 G .781
(ackslash escape to)429.128 201.6 R .007
(cause the shell to change its prompt when running as root after an)72 213.6 R
/F3 10/Times-Italic@0 SF(su)2.507 E F0 5.007(.B)C .007
(efore printing each primary prompt,)360.392 213.6 R .305(Bash e)72 225.6 R
.305(xpands the v)-.15 F(ariable)-.25 E F2($PR)2.805 E(OMPT_COMMAND)-.3 E F0
.305(and, if it has a v)2.805 F .306(alue, e)-.25 F -.15(xe)-.15 G .306
(cutes the e).15 F .306(xpanded v)-.15 F .306(alue as)-.25 F 3.735(ac)72 237.6
S 1.235(ommand, allo)84.615 237.6 R 1.234
(wing additional prompt customization.)-.25 F -.15(Fo)6.234 G 3.734(re).15 G
1.234(xample, this assignment causes the current)327.3 237.6 R(user)72 249.6 Q
2.917(,t)-.4 G .417
(he current host, the time, the last component of the current w)96.457 249.6 R
.417(orking directory)-.1 F 2.917(,t)-.65 G .418(he le)417.188 249.6 R -.15(ve)
-.25 G 2.918(lo).15 G 2.918(fs)456.504 249.6 S .418(hell nest-)466.642 249.6 R
(ing, and the history number of the current command to be embedded into the pr\
imary prompt:)72 261.6 Q F1 6($P)97 279.6 S
(S1='\\u@\\h [\\t] \\W\($SHLVL:\\!\)\\$ ')115 279.6 Q
(chet@odin [21:03:44] documentation\(2:636\)$ cd ..)97 291.6 Q
(chet@odin [21:03:54] src\(2:637\)$)97 303.6 Q F0 .146
(The string being assigned is surrounded by single quotes so that if it is e)72
325.2 R .146(xported, the v)-.15 F .146(alue of)-.25 F F2($SHL)2.646 E(VL)-.92
E F0(will)2.646 E(be updated by a child shell:)72 337.2 Q F1
(chet@odin [21:17:35] src\(2:638\)$ export PS1)97 355.2 Q
(chet@odin [21:17:40] src\(2:639\)$ bash)97 367.2 Q
(chet@odin [21:17:46] src\(3:696\)$)97 379.2 Q F0
(The \\$ escape is displayed as `)72 400.8 Q(`)-.74 E F2($)A F0 1.48 -.74('' w)
D(hen running as a normal user).74 E 2.5(,b)-.4 G(ut as `)342.08 400.8 Q(`)-.74
E F2(#)A F0 1.48 -.74('' w)D(hen running as root.).74 E F2 2.5(4.9. File)72
424.8 R(System V)2.5 E(iews)-.37 E F0 .029(Since Berk)97 440.4 R(ele)-.1 E
2.529(yi)-.15 G .029
(ntroduced symbolic links in 4.2 BSD, one of their most anno)162.908 440.4 R
.03(ying properties has been)-.1 F 1.701(the `)72 452.4 R(`w)-.74 E(arping')-.1
E 4.201('t)-.74 G 4.201(oac)139.912 452.4 S 1.701(ompletely dif)162.194 452.4 R
1.701(ferent area of the \214le system when using)-.25 F F2(cd)4.2 E F0 4.2(,a)
C 1.7(nd the resultant non-)416.41 452.4 R(intuiti)72 464.4 Q .658 -.15(ve b)
-.25 H(eha).15 E .359(vior of `)-.2 F(`)-.74 E F2 .359(cd ..)B F0 -.74('')C
5.359(.T).74 G(he)200.304 464.4 Q/F4 9/Times-Roman@0 SF(UNIX)2.859 E F0 -.1(ke)
2.859 G .359(rnel treats symbolic links).1 F F3(physically)2.859 E F0 5.359(.W)
1.666 G .359(hen the k)411.574 464.4 R .359(ernel is trans-)-.1 F .401(lating \
a pathname in which one component is a symbolic link, it replaces all or part \
of the pathname while)72 476.4 R .946(processing the link.)72 488.4 R .946
(If the contents of the symbolic link be)5.946 F .946(gin with a slash, the k)
-.15 F .947(ernel replaces the path-)-.1 F .661
(name entirely; if not, the link contents replace the current component.)72
500.4 R .66(In either case, the symbolic link is)5.66 F 2.546(visible. If)72
512.4 R .046(the link v)2.546 F .047
(alue is an absolute pathname, the user \214nds himself in a completely dif)
-.25 F .047(ferent part of the)-.25 F(\214le system.)72 524.4 Q .599(Bash pro)
97 540 R .599(vides a)-.15 F F3(lo)3.099 E(gical)-.1 E F0(vie)4.765 E 3.099(wo)
-.25 G 3.099(ft)224.761 540 S .599(he \214le system.)233.97 540 R .599
(In this def)5.599 F .599(ault mode, command and \214lename com-)-.1 F .522
(pletion and b)72 552 R .522(uiltin commands such as)-.2 F F2(cd)3.022 E F0
(and)3.022 E F2(pushd)3.022 E F0 .522(which change the current w)3.022 F .522
(orking directory transpar)-.1 F(-)-.2 E .127(ently follo)72 564 R 2.627(ws)
-.25 G .127(ymbolic links as if the)127.004 564 R 2.627(yw)-.15 G .127
(ere directories.)231.099 564 R(The)5.126 E F2($PWD)2.626 E F0 -.25(va)2.626 G
.126(riable, which holds the shell').25 F 2.626(si)-.55 G .126(dea of)479.164
564 R .366(the current w)72 576 R .366(orking directory)-.1 F 2.866(,d)-.65 G
.367(epends on the path used to reach the directory rather than its ph)200.184
576 R .367(ysical loca-)-.05 F(tion in the local \214le system hierarch)72 588
Q 3.8 -.65(y. F)-.05 H(or e).5 E(xample:)-.15 E F1 6($c)97 606 S 6(d/)115 606 S
(usr/local/bin)133 606 Q 6($e)97 618 S(cho $PWD)115 618 Q(/usr/local/bin)97 630
Q 6($p)97 642 S(wd)115 642 Q(/usr/local/bin)97 654 Q 6($/)97 666 S(bin/pwd)115
666 Q(/net/share/sun4/local/bin)97 678 Q 6($c)97 690 S 6(d.)115 690 S(.)133 690
Q 6($p)97 702 S(wd)115 702 Q(/usr/local)97 714 Q 6($/)97 726 S(bin/pwd)115 726
Q EP
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/F0 10/Times-Roman@0 SF 2.5(-8-)279.67 48 S/F1 10/Courier@0 SF
(/net/share/sun4/local)97 84 Q 6($c)97 96 S 6(d.)115 96 S(.)133 96 Q 6($p)97
108 S(wd)115 108 Q(/usr)97 120 Q 6($/)97 132 S(bin/pwd)115 132 Q(/usr)97 144 Q
F0 .3(One problem with this, of course, arises when programs that do not under\
stand the shell')72 165.6 R 2.8(sl)-.55 G .3(ogical notion of)440.07 165.6 R
.717(the \214le system interpret `)72 177.6 R(`..)-.74 E 2.197 -.74('' d)-.7 H
(if).74 E(ferently)-.25 E 5.717(.T)-.65 G .717
(his generally happens when Bash completes \214lenames contain-)246.521 177.6 R
.977(ing `)72 189.6 R(`..)-.74 E 2.457 -.74('' a)-.7 H .977
(ccording to a logical hierarch).74 F 3.476(yw)-.05 G .976
(hich does not correspond to their ph)249.056 189.6 R .976(ysical location.)
-.05 F -.15(Fo)5.976 G 3.476(ru).15 G(sers)488.45 189.6 Q
(who \214nd this troublesome, a corresponding)72 201.6 Q/F2 10/Times-Italic@0
SF(physical)2.5 E F0(vie)4.166 E 2.5(wo)-.25 G 2.5(ft)312.006 201.6 S
(he \214le system is a)320.616 201.6 Q -.25(va)-.2 G(ilable:).25 E F1 6($c)97
219.6 S 6(d/)115 219.6 S(usr/local/bin)133 219.6 Q 6($p)97 231.6 S(wd)115 231.6
Q(/usr/local/bin)97 243.6 Q 6($s)97 255.6 S(et -o physical)115 255.6 Q 6($p)97
267.6 S(wd)115 267.6 Q(/net/share/sun4/local/bin)97 279.6 Q/F3 10/Times-Bold@0
SF 2.5(4.10. Inter)72 309.6 R(nationalization)-.15 E F0 .052
(One of the most signi\214cant impro)97 325.2 R -.15(ve)-.15 G .052(ments in v)
.15 F .053(ersion 1.13 of Bash w)-.15 F .053(as the change to `)-.1 F .053
(`eight-bit clean-)-.74 F(liness')72 337.2 Q 2.846('. Pre)-.74 F .346(vious v)
-.25 F .345
(ersions used the eighth bit of characters to mark whether or not the)-.15 F
2.845(yw)-.15 G .345(ere quoted when)437.22 337.2 R 1.495(performing w)72 349.2
R 1.495(ord e)-.1 F 3.995(xpansions. While)-.15 F 1.495(this did not af)3.995 F
1.496(fect the majority of users, most of whom used only)-.25 F(se)72 361.2 Q
-.15(ve)-.25 G 1.236(n-bit ASCII characters, some found it con\214ning.).15 F
(Be)6.236 E 1.236(ginning with v)-.15 F 1.236(ersion 1.13, Bash implemented a)
-.15 F(dif)72 373.2 Q .02
(ferent quoting mechanism that did not alter the eighth bit of characters.)-.25
F .021(This allo)5.021 F .021(wed Bash to manipulate)-.25 F .263
(\214les with `)72 385.2 R(`odd')-.74 E 2.763('c)-.74 G .262
(haracters in their names, b)146.019 385.2 R .262
(ut did nothing to help users enter those names, so v)-.2 F .262(ersion 1.13)
-.15 F 1.458
(introduced changes to readline that made it eight-bit clean as well.)72 397.2
R 1.458(Options e)6.458 F 1.458(xist that force readline to)-.15 F .744(attach\
 no special signi\214cance to characters with the eighth bit set \(the def)72
409.2 R .744(ault beha)-.1 F .744(vior is to con)-.2 F -.15(ve)-.4 G .744
(rt these).15 F 1.88(characters to meta-pre\214x)72 421.2 R 1.88(ed k)-.15 F
2.18 -.15(ey s)-.1 H 1.88
(equences\) and to output these characters without con).15 F -.15(ve)-.4 G 1.88
(rsion to meta-).15 F(pre\214x)72 433.2 Q .582(ed sequences.)-.15 F .581
(These changes, along with the e)5.582 F .581(xpansion of k)-.15 F -.15(ey)-.1
G .581(maps to a full eight bits, enable read-).15 F(line to w)72 445.2 Q
(ork with most of the ISO-8859 f)-.1 E(amily of character sets, used by man)-.1
E 2.5(yE)-.15 G(uropean countries.)394.94 445.2 Q F3 2.5(4.11. POSIX)72 469.2 R
(Mode)2.5 E F0 .584(Although Bash is intended to be POSIX.2 conformant, there \
are areas in which the def)97 484.8 R .584(ault beha)-.1 F(vior)-.2 E .463
(is not compatible with the standard.)72 496.8 R -.15(Fo)5.463 G 2.962(ru).15 G
.462(sers who wish to operate in a strict POSIX.2 en)244.25 496.8 R .462
(vironment, Bash)-.4 F .505(implements a)72 508.8 R F2 .505(POSIX mode)3.005 F
F0 5.505(.W)C .505(hen this mode is acti)199 508.8 R -.15(ve)-.25 G 3.005(,B)
.15 G .505(ash modi\214es its def)304.455 508.8 R .505
(ault operation where it dif)-.1 F(fers)-.25 E .267
(from POSIX.2 to match the standard.)72 520.8 R .266
(POSIX mode is entered when Bash is started with the)5.267 F F3(-posix)2.766 E
F0(option.)2.766 E .149(This feature is also a)72 532.8 R -.25(va)-.2 G .149
(ilable as an option to the).25 F F3(set)2.649 E F0 -.2(bu)2.649 G(iltin,).2 E
F3 .149(set -o posix)2.649 F F0 5.149(.F)C .149
(or compatibility with other GNU)371.744 532.8 R(softw)72 544.8 Q 4.02(are tha\
t attempts to be POSIX.2 compliant, Bash also enters POSIX mode if the v)-.1 F
(ariable)-.25 E F3($POSIXL)72 556.8 Q(Y_CORRECT)-.92 E F0 5.824
(is set when Bash is started or assigned a v)8.324 F 5.825(alue during e)-.25 F
-.15(xe)-.15 G(cution.).15 E F3($POSIX_PED)72 568.8 Q(ANTIC)-.35 E F0 .27
(is accepted as well, to be compatible with some older GNU utilities.)2.77 F
.27(When Bash is)5.27 F .428(started in POSIX mode, for e)72 580.8 R .428
(xample, it sources the \214le named by the v)-.15 F .429(alue of)-.25 F F3
($ENV)2.929 E F0 .429(rather than the `)2.929 F(`nor)-.74 E(-)-.2 E(mal')72
592.8 Q 2.5('s)-.74 G(tartup \214les, and does not allo)99.31 592.8 Q 2.5(wr)
-.25 G(eserv)227.66 592.8 Q(ed w)-.15 E(ords to be aliased.)-.1 E F3 2.5
(5. New)72 616.8 R -.25(Fe)2.5 G(atur).25 E(es and Futur)-.18 E 2.5(eP)-.18 G
(lans)201.65 616.8 Q F0 1.632(There are se)97 632.4 R -.15(ve)-.25 G 1.632
(ral features introduced in the current v).15 F 1.631(ersion of Bash, v)-.15 F
1.631(ersion 1.14, and a number)-.15 F .241
(under consideration for future releases.)72 644.4 R .242
(This section will brie\215y detail the ne)5.242 F 2.742(wf)-.25 G .242
(eatures in v)395.702 644.4 R .242(ersion 1.14 and)-.15 F(describe se)72 656.4
Q -.15(ve)-.25 G(ral features that may appear in later v).15 E(ersions.)-.15 E
F3 2.5(5.1. New)72 680.4 R -.25(Fe)2.5 G(atur).25 E(es in Bash-1.14)-.18 E F0
.884(The ne)97 696 R 3.384(wf)-.25 G .884(eatures a)139.058 696 R -.25(va)-.2 G
.884(ilable in Bash-1.14 answer se).25 F -.15(ve)-.25 G .883
(ral of the most common requests for enhance-).15 F 2.931(ments. Most)72 708 R
(notably)2.931 E 2.931(,t)-.65 G .432(here is a mechanism for including non-vi\
sible character sequences in prompts, such)164.873 708 R 1.533
(as those which cause a terminal to print characters in dif)72 720 R 1.532
(ferent colors or in standout mode.)-.25 F 1.532(There w)6.532 F(as)-.1 E EP
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/F0 10/Times-Roman@0 SF 2.5(-9-)279.67 48 S 1.967(nothing pre)72 84 R -.15(ve)
-.25 G 1.967(nting the use of these sequences in earlier v).15 F 1.967
(ersions, b)-.15 F 1.967(ut the readline redisplay algorithm)-.2 F
(assumed each character occupied ph)72 96 Q(ysical screen space and w)-.05 E
(ould wrap lines prematurely)-.1 E(.)-.65 E .13(Readline has a fe)97 111.6 R
2.63(wn)-.25 G .63 -.25(ew va)180.58 111.6 T .13(riables, se).25 F -.15(ve)-.25
G .13(ral ne).15 F 2.63(wb)-.25 G .13
(indable commands, and some additional emacs mode)290.19 111.6 R(def)72 123.6 Q
.918(ault k)-.1 F 1.218 -.15(ey b)-.1 H 3.418(indings. A).15 F(ne)3.418 E 3.418
(wh)-.25 G .919
(istory search mode has been implemented: in this mode, readline searches)
199.03 123.6 R .336(the history for lines be)72 135.6 R .336
(ginning with the characters between the be)-.15 F .336
(ginning of the current line and the cursor)-.15 F(.)-.55 E .555(The e)72 147.6
R .556(xisting readline incremental search commands no longer match identical \
lines more than once.)-.15 F(File-)5.556 E 1.979(name completion no)72 159.6 R
4.479(we)-.25 G 1.979(xpands v)173.357 159.6 R 1.979
(ariables in directory names.)-.25 F 1.978(The history e)6.978 F 1.978
(xpansion f)-.15 F 1.978(acilities are no)-.1 F(w)-.25 E 1.449
(nearly completely csh-compatible: missing modi\214ers ha)72 171.6 R 1.749 -.15
(ve b)-.2 H 1.449(een added and history substitution has been).15 F -.15(ex)72
183.6 S(tended.).15 E(Se)97 199.2 Q -.15(ve)-.25 G .474
(ral of the features described earlier).15 F 2.973(,s)-.4 G .473(uch as)266.483
199.2 R/F1 10/Times-Bold@0 SF .473(set -o posix)2.973 F F0(and)2.973 E F1
($POSIX_PED)2.973 E(ANTIC)-.35 E F0 2.973(,a)C .473(re ne)466.094 199.2 R 2.973
(wi)-.25 G(n)499 199.2 Q -.15(ve)72 211.2 S .106(rsion 1.14.).15 F .106
(There is a ne)5.106 F 2.606(ws)-.25 G .106(hell v)194.156 211.2 R(ariable,)
-.25 E F1(OSTYPE)2.606 E F0 2.606(,t)C 2.606(ow)296.724 211.2 S .106
(hich Bash assigns a v)311.55 211.2 R .106(alue that identi\214es the v)-.25 F
(er)-.15 E(-)-.2 E 1.38(sion of)72 223.2 R/F2 9/Times-Roman@0 SF(UNIX)3.88 E F0
(it')3.88 E 3.879(sr)-.55 G 1.379(unning on \(great for putting architecture-s\
peci\214c binary directories into the)150.57 223.2 R F1($P)3.879 E -.95(AT)-.74
G(H).95 E F0(\).)A -1 -.8(Tw o)72 235.2 T -.25(va)6.215 G 2.915(riables ha).25
F 3.215 -.15(ve b)-.2 H 2.915(een renamed:).15 F F1($HISTCONTR)5.416 E(OL)-.3 E
F0(replaces)5.416 E F1($history_contr)5.416 E(ol)-.18 E F0 5.416(,a)C(nd)
432.454 235.2 Q F1($HOSTFILE)5.416 E F0(replaces)72 247.2 Q F1
($hostname_completion_\214le)2.521 E F0 5.021(.I)C 2.521(nb)234.242 247.2 S
.021(oth cases, the old names are accepted for backw)246.763 247.2 R .02
(ards compatibil-)-.1 F(ity)72 259.2 Q 5.676(.T)-.65 G .677(he ksh)96.196 259.2
R/F3 10/Times-Italic@0 SF(select)3.177 E F0 .677(construct, which allo)4.843 F
.677(ws the generation of simple menus, has been implemented.)-.25 F(Ne)5.677 E
(w)-.25 E 2.892(capabilities ha)72 271.2 R 3.192 -.15(ve b)-.2 H 2.892
(een added to e).15 F 2.892(xisting v)-.15 F(ariables:)-.25 E F1($auto_r)5.392
E(esume)-.18 E F0 2.892(can no)5.392 F 5.392(wt)-.25 G(ak)404.13 271.2 Q 5.391
(ev)-.1 G 2.891(alues of)428.051 271.2 R F3 -.2(ex)5.391 G(act).2 E F0(or)7.057
E F3(substring)72 283.2 Q F0 3.278(,a)1.666 G(nd)121.114 283.2 Q F1($HISTCONTR)
3.278 E(OL)-.3 E F0 .778(understands the v)3.278 F(alue)-.25 E F3(ignor)3.278 E
(eboth)-.37 E F0 3.278(,w)1.666 G .778(hich combines the tw)366.248 283.2 R
3.278(op)-.1 G(re)467.03 283.2 Q(viously)-.25 E 1.556(acceptable v)72 295.2 R
4.056(alues. The)-.25 F F1(dirs)4.056 E F0 -.2(bu)4.056 G 1.556
(iltin has acquired options to print out speci\214c members of the directory).2
F 3.062(stack. The)72 307.2 R F1($nolinks)3.062 E F0 -.25(va)3.062 G .562
(riable, which forces a ph).25 F .562(ysical vie)-.05 F 3.062(wo)-.25 G 3.062
(ft)322.028 307.2 S .563(he \214le system, has been superseded by the)331.2
307.2 R F1<ad50>72 319.2 Q F0 .494(option to the)2.994 F F1(set)2.994 E F0 -.2
(bu)2.994 G .494(iltin \(equi).2 F -.25(va)-.25 G .494(lent to).25 F F1 .494
(set -o ph)2.994 F(ysical)-.15 E F0 .493(\); the v)B .493
(ariable is retained for backw)-.25 F .493(ards compati-)-.1 F(bility)72 331.2
Q 5.196(.T)-.65 G .196(he v)106.276 331.2 R .196(ersion string contained in)
-.15 F F1($B)2.696 E(ASH_VERSION)-.3 E F0(no)2.696 E 2.696(wi)-.25 G .196
(ncludes an indication of the patch le)335.558 331.2 R -.15(ve)-.25 G 2.696(la)
.15 G(s)500.11 331.2 Q .665(well as the `)72 343.2 R(`b)-.74 E .665(uild v)-.2
F(ersion')-.15 E 3.165('. Some)-.74 F .665(little-used features ha)3.165 F .965
-.15(ve b)-.2 H .665(een remo).15 F -.15(ve)-.15 G 3.165(d: the).15 F F1(by)
3.165 E(e)-.1 E F0(synon)3.165 E .665(ym for)-.15 F F1(exit)3.165 E F0(and)
3.165 E(the)72 355.2 Q F1($NO_PR)3.498 E(OMPT_V)-.3 E(ARS)-1.35 E F0 -.25(va)
3.498 G .998(riable are gone.).25 F .998(There is no)5.998 F 3.498(wa)-.25 G
3.498(no)331.114 355.2 S -2.19 -.18(rg a)344.612 355.2 T .998
(nized test suite that can be run as a).18 F(re)72 367.2 Q
(gression test when b)-.15 E(uilding a ne)-.2 E 2.5(wv)-.25 G(ersion of Bash.)
222.34 367.2 Q 1.696(The documentation has been thoroughly o)97 382.8 R -.15
(ve)-.15 G 1.696(rhauled: there is a ne).15 F 4.196(wm)-.25 G 1.695
(anual page on the readline)392.25 382.8 R .467(library and the)72 394.8 R F3
(info)2.967 E F0 .467(\214le has been updated to re\215ect the current v)2.967
F 2.968(ersion. As)-.15 F(al)2.968 E -.1(wa)-.1 G .468(ys, as man).1 F 2.968
(yb)-.15 G .468(ugs as possi-)451.954 394.8 R(ble ha)72 406.8 Q .3 -.15(ve b)
-.2 H(een \214x).15 E(ed, although some surely remain.)-.15 E F1 2.5
(5.2. Other)72 430.8 R -.25(Fe)2.5 G(atur).25 E(es)-.18 E F0 1.68
(There are a fe)97 446.4 R 4.18(wf)-.25 G 1.68
(eatures that I hope to include in later Bash releases.)171.76 446.4 R 1.68
(Some are based on w)6.68 F(ork)-.1 E(already done in other shells.)72 458.4 Q
.958(In addition to simple v)97 474 R .959
(ariables, a future release of Bash will include one-dimensional arrays, using)
-.25 F .206(the ksh implementation of arrays as a model.)72 486 R .205
(Additions to the ksh syntax, such as)5.205 F F3(varname)2.705 E F0 .205
(=\( ... \) to assign)B 2.587(al)72 498 S .087(ist of w)81.807 498 R .088
(ords directly to an array and a mechanism to allo)-.1 F 2.588(wt)-.25 G(he)
320.248 498 Q F1 -.18(re)2.588 G(ad).18 E F0 -.2(bu)2.588 G .088
(iltin to read a list of v).2 F .088(alues directly)-.25 F .092(into an array)
72 510 R 2.592(,w)-.65 G .092(ould be desirable.)134.286 510 R(Gi)5.092 E -.15
(ve)-.25 G 2.592(nt).15 G .092(hose e)239.794 510 R .092(xtensions, the ksh)
-.15 F F1 .092(set \255A)2.592 F F0 .091(syntax may not be w)2.591 F .091
(orth support-)-.1 F(ing \(the)72 522 Q F1<ad41>2.5 E F0
(option assigns a list of v)2.5 E(alues to an array)-.25 E 2.5(,b)-.65 G
(ut is a rather peculiar special case\).)292.41 522 Q .76
(Some shells include a means of)97 537.6 R F3(pr)3.26 E -.1(og)-.45 G -.15(ra)
.1 G(mmable).15 E F0 -.1(wo)3.26 G .76
(rd completion, where the user speci\214es on a per).1 F(-)-.2 E .163
(command basis ho)72 549.6 R 2.663(wt)-.25 G .163(he ar)159.179 549.6 R .163(g\
uments of the command are to be treated when completion is attempted: as \214l\
e-)-.18 F .194(names, hostnames, e)72 561.6 R -.15(xe)-.15 G .194
(cutable \214les, and so on.).15 F .195
(The other aspects of the current Bash implementation could)5.195 F .482
(remain as-is; the e)72 573.6 R .482(xisting heuristics w)-.15 F .481
(ould still be v)-.1 F 2.981(alid. Only)-.25 F .481(when completing the ar)
2.981 F .481(guments to a simple)-.18 F(command w)72 585.6 Q
(ould the programmable completion be in ef)-.1 E(fect.)-.25 E .479(It w)97
601.2 R .479(ould also be nice to gi)-.1 F .779 -.15(ve t)-.25 H .479
(he user \214ner).15 F .479(-grained control o)-.2 F -.15(ve)-.15 G 2.98(rw).15
G .48(hich commands are sa)363.92 601.2 R -.15(ve)-.2 G 2.98(do).15 G .48
(nto the)476.02 601.2 R 1.786(history list.)72 613.2 R 1.786
(One proposal is for a v)6.786 F 1.786(ariable, tentati)-.25 F -.15(ve)-.25 G
1.786(ly named).15 F F1(HISTIGNORE)4.286 E F0 4.285(,w)C 1.785(hich w)415.145
613.2 R 1.785(ould contain a)-.1 F .496(colon-separated list of commands.)72
625.2 R .496(Lines be)5.496 F .496
(ginning with these commands, after the restrictions of)-.15 F F1($HIST)2.997 E
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(een applied, w).15 F .15(ould not be placed onto the history list.)-.1 F .15
(The shell pattern-matching capa-)5.15 F(bilities could also be a)72 649.2 Q
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3.23(\)p)C(ro)370.79 664.8 Q .73(vide is a command to dynami-)-.15 F 1.189
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2.69(no)95.69 688.8 S .19(bject \214le or shared library implementing the `)
108.38 688.8 R(`body')-.74 E 2.69('o)-.74 G 2.69(ft)327.83 688.8 S .19(he b)
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2.552(wc)-.25 G .051(ommand, the function to call when the)349.544 700.8 R(ne)
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(presumably de\214ned in the shared object speci\214ed as an ar)169.682 712.8 R
.959(gument\), and the docu-)-.18 F 1.352(mentation to be printed by the)72
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6.351 F(ould)-.1 E EP
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(alue for)-.1 F F1($P)3.464 E -.95(AT)-.74 G(H).95 E F0 .964
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147.6 R(directory)72 159.6 Q(.)-.65 E 1.521
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175.2 R(include them.)72 187.2 Q(If an)5 E
(yone has comments on these proposals, feel free to send me electronic mail.)
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(In the original description of the Bourne shell, quoting and)5.093 F .073(the\
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1.375(Nobody really kno)97 290.4 R 1.375(ws what the Bourne shell')-.25 F 3.875
(sg)-.55 G 1.375(rammar is.)296.635 290.4 R(Ev)6.376 E 1.376(en e)-.15 F 1.376
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F0 .382(grammar that comes close to capturing the Bourne shell')2.882 F 2.882
(sb)-.55 G(eha)472.11 318 Q(vior)-.2 E(,)-.4 E -.2(bu)72 330 S 3.246(ti).2 G
3.246(td)90.606 330 S(isallo)101.632 330 Q .747(ws some constructs which sh ac\
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(ug reports before Bash implemented sh-compatible quoting,)-.2 F .094
(and there are still some `)72 354 R(`le)-.74 E -.05(ga)-.15 G(l').05 E 2.594
('s)-.74 G 2.594(hc)205.294 354 S .094
(onstructs which Bash \215ags as syntax errors.)217.328 354 R .095
(Complete sh compatibility)5.095 F(is a tough nut.)72 366 Q 1.231
(The shell is bigger and slo)97 381.6 R 1.231(wer than I w)-.25 F 1.231
(ould lik)-.1 F 1.23(e, though the current v)-.1 F 1.23
(ersion is substantially f)-.15 F(aster)-.1 E .086(than pre)72 393.6 R(viously)
-.25 E 5.086(.T)-.65 G .087(he readline library could stand a substantial re)
146.822 393.6 R 2.587(write. A)-.25 F .087(hand-written parser to replace the)
2.587 F(current)72 405.6 Q F4(yacc)2.978 E F0 .478(-generated one w)B .477
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(shell could parse commands in `)72 417.6 R(`$\(...\)')-.74 E 2.699('c)-.74 G
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(re entered, rather than reporting errors when the)311.001 417.6 R
(construct is e)72 429.6 Q(xpanded.)-.15 E 1.064(As al)97 445.2 R -.1(wa)-.1 G
1.064(ys, there is some chaf).1 F 3.564(ft)-.25 G 3.564(og)230.404 445.2 S
3.564(ow)243.968 445.2 S 1.064(ith the wheat.)259.752 445.2 R 1.063
(Areas of duplicated functionality need to be)6.063 F .382(cleaned up.)72 457.2
R .382(There are se)5.382 F -.15(ve)-.25 G .382
(ral cases where Bash treats a v).15 F .382
(ariable specially to enable functionality a)-.25 F -.25(va)-.2 G(ilable).25 E
.185(another w)72 469.2 R .185(ay \()-.1 F F1($notify)A F0(vs.)2.684 E F1 .184
(set -o notify)5.184 F F0(and)2.684 E F1($nolinks)2.684 E F0(vs.)2.684 E F1
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E F0(and)4.112 E F1($glob_dot_\214lenames)4.112 E F0 -.25(va)4.111 G 1.611
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F1($[...])3.977 E F0 1.477(arithmetic e)3.977 F -.25(va)-.25 G 1.478
(luation syntax is redundant no).25 F 3.978(wt)-.25 G 1.478
(hat the POSIX-mandated)312.76 505.2 R F1($\(\(...\)\))3.978 E F0 1.478
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F F1(help)2.825 E F0 -.2(bu)2.825 G .325(iltin were e).2 F(xter)-.15 E(-)-.2 E
.061(nal to the shell rather than compiled into it.)72 529.2 R .062(The beha)
5.062 F .062(vior enabled by)-.2 F F1($command_oriented_history)2.562 E F0
2.562(,w)C(hich)486.78 529.2 Q 1.125(causes the shell to attempt to sa)72 541.2
R 1.424 -.15(ve a)-.2 H 1.124
(ll lines of a multi-line command in a single history entry).15 F 3.624(,s)-.65
G 1.124(hould be)468.156 541.2 R(made the def)72 553.2 Q(ault and the v)-.1 E
(ariable remo)-.25 E -.15(ve)-.15 G(d.).15 E F1 2.5(7. A)72 577.2 R -.1(va)-1 G
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(are, Bash is a)-.1 F -.25(va)-.2 G 8.539(ilable for anon).25 F 8.539
(ymous FTP from)-.15 F F4(pr)72 604.8 Q(ep.ai.mit.edu:/pub/gnu)-.37 E F0 4.552
(and from other GNU softw)8.718 F 4.552(are mirror sites.)-.1 F 4.552
(The current v)9.552 F 4.552(ersion is in)-.15 F F4(bash-1.14.1.tar)72 616.8 Q
(.gz)-1.11 E F0 .074(in that directory)4.24 F 5.075(.U)-.65 G(se)226.084 616.8
Q F4(ar)2.575 E -.15(ch)-.37 G(ie).15 E F0 .075(to \214nd the nearest archi)
4.241 F .375 -.15(ve s)-.25 H 2.575(ite. The).15 F .075(latest v)2.575 F .075
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(ilable for FTP from).25 F F4(bash.CWR)72 640.8 Q -.25(U.)-.4 G(Edu:/pub/bash.)
.25 E F0 1.168(The Free Softw)97 656.4 R 1.168(are F)-.1 F 1.168
(oundation sells tapes and CD-R)-.15 F 1.169
(OMs containing Bash; send electronic mail to)-.4 F F3(gnu@prep.ai.mit.edu)72
668.4 Q F0(or call)2.5 E F3(+1-617-876-3296)2.5 E F0(for more information.)2.5
E .32 LW 76 678.4 72 678.4 DL 80 678.4 76 678.4 DL 84 678.4 80 678.4 DL 88
678.4 84 678.4 DL 92 678.4 88 678.4 DL 96 678.4 92 678.4 DL 100 678.4 96 678.4
DL 104 678.4 100 678.4 DL 108 678.4 104 678.4 DL 112 678.4 108 678.4 DL 116
678.4 112 678.4 DL 120 678.4 116 678.4 DL 124 678.4 120 678.4 DL 128 678.4 124
678.4 DL 132 678.4 128 678.4 DL 136 678.4 132 678.4 DL 140 678.4 136 678.4 DL
144 678.4 140 678.4 DL/F5 8/Times-Roman@0 SF 1.39(\207S. R. Bourne, `)72 688.4
R 1.389(`UNIX T)-.592 F 1.389(ime-Sharing System:)-.28 F 1.389(The UNIX Shell')
5.389 F(',)-.592 E/F6 8/Times-Italic@0 SF 1.389(Bell System T)3.389 F(ec)-.736
E 1.389(hnical J)-.12 F(ournal)-.2 E F5 3.389(,5)C 1.389(7\(6\), July-August,)
408.171 688.4 R(1978, pp. 1971-1990.)72 698.4 Q<8854>72 708.4 Q .684(om Duf)
-.64 F .684(f, `)-.2 F .684(`Rc \255 A Shell for Plan 9 and)-.592 F/F7 7
/Times-Roman@0 SF(UNIX)2.684 E F5(systems')2.684 E(',)-.592 E F6(Pr)2.684 E
.684(oc. of the Summer 1990 EUUG Confer)-.36 F(ence)-.296 E F5 2.685(,L)C .685
(ondon, July)428.499 708.4 R(,)-.52 E(1990, pp. 21-33.)72 718.4 Q EP
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/F0 10/Times-Roman@0 SF 2.5(-1)277.17 48 S 2.5(1-)288 48 S .695
(Bash is also distrib)97 84 R .694(uted with se)-.2 F -.15(ve)-.25 G .694
(ral v).15 F .694(ersions of)-.15 F/F1 9/Times-Roman@0 SF(UNIX)3.194 E F0 .694
(-compatible systems.)B .694(It is included as /bin/sh)5.694 F .948
(and /bin/bash on se)72 96 R -.15(ve)-.25 G .948(ral Linux distrib).15 F .948
(utions \(more about the dif)-.2 F .948(ference in a moment\), and as contrib)
-.25 F(uted)-.2 E(softw)72 108 Q(are in BSDI')-.1 E 2.5(sB)-.55 G
(SD/386* and FreeBSD.)157.73 108 Q .599(The Linux distrib)97 123.6 R .599
(ution deserv)-.2 F .599(es special mention.)-.15 F .598(There are tw)5.599 F
3.098(oc)-.1 G .598(on\214gurations included in the stan-)364.948 123.6 R .547
(dard Bash distrib)72 135.6 R .547(ution: a `)-.2 F(`normal')-.74 E 3.047('c)
-.74 G .548
(on\214guration, in which all of the standard features are included, and a)
222.755 135.6 R -.74(``)72 147.6 S(minimal').74 E 2.792('c)-.74 G .292(on\214g\
uration, which omits job control, aliases, history and command line editing, t\
he directory)124.412 147.6 R .747(stack and)72 159.6 R/F2 10/Times-Bold@0 SF
(pushd/popd/dirs,)3.247 E F0 .747
(process substitution, prompt string special character decoding, and the)3.247
F/F3 10/Times-Italic@0 SF(select)3.247 E F0 3.369(construct. This)72 171.6 R
.869(minimal v)3.369 F .869
(ersion is designed to be a drop-in replacement for the traditional)-.15 F F1
(UNIX)3.368 E F0(/bin/sh,)3.368 E(and is included as the Linux /bin/sh in se)72
183.6 Q -.15(ve)-.25 G(ral packagings.).15 E F2 2.5(8. Conclusion)72 207.6 R F0
.8(Bash is a w)97 223.2 R(orth)-.1 E 3.3(ys)-.05 G .8(uccessor to sh.)173.379
223.2 R .8(It is suf)5.8 F .8(\214ciently portable to run on nearly e)-.25 F
-.15(ve)-.25 G .8(ry v).15 F .8(ersion of)-.15 F F1(UNIX)3.3 E F0 .311
(from 4.3 BSD to SVR4.2, and se)72 235.2 R -.15(ve)-.25 G(ral).15 E F1(UNIX)
2.811 E F0 -.1(wo)2.811 G(rkalik).1 E 2.811(es. It)-.1 F .31(is rob)2.81 F .31
(ust enough to replace sh on most of those)-.2 F 1.515(systems, and pro)72
247.2 R 1.515(vides more functionality)-.15 F 6.515(.I)-.65 G 4.015(th)254.315
247.2 S 1.515(as se)266.11 247.2 R -.15(ve)-.25 G 1.515(ral thousand re).15 F
1.515(gular users, and their feedback has)-.15 F(helped to mak)72 259.2 Q 2.5
(ei)-.1 G 2.5(ta)138.28 259.2 S 2.5(sg)148 259.2 S
(ood as it is today \255 a testament to the bene\214ts of free softw)159.39
259.2 Q(are.)-.1 E .32 LW 76 698 72 698 DL 80 698 76 698 DL 84 698 80 698 DL 88
698 84 698 DL 92 698 88 698 DL 96 698 92 698 DL 100 698 96 698 DL 104 698 100
698 DL 108 698 104 698 DL 112 698 108 698 DL 116 698 112 698 DL 120 698 116 698
DL 124 698 120 698 DL 128 698 124 698 DL 132 698 128 698 DL 136 698 132 698 DL
140 698 136 698 DL 144 698 140 698 DL/F4 8/Times-Roman@0 SF
(*BSD/386 is a trademark of Berk)72 708 Q(ele)-.08 E 2(yS)-.12 G(oftw)198.896
708 Q(are Design, Inc.)-.08 E EP
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