oslib.c

   1 /* oslib.c - functions present only in some unix versions. */
   2
   3 /* Copyright (C) 1995 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software; you can redistribute it and/or modify it under
   8    the terms of the GNU General Public License as published by the Free
   9    Software Foundation; either version 2, or (at your option) any later
  10    version.
  11
  12    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15    for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with Bash; see the file COPYING.  If not, write to the Free Software
  19    Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #include "config.h"
  22
  23 #include "bashtypes.h"
  24 #include <sys/param.h>
  25
  26 #if defined (HAVE_UNISTD_H)
  27 #  include <unistd.h>
  28 #endif
  29
  30 #include "posixstat.h"
  31 #include "filecntl.h"
  32 #include "bashansi.h"
  33
  34 #include <stdio.h>
  35 #include <errno.h>
  36 #include <ctype.h>
  37
  38 #include "shell.h"
  39 #include "maxpath.h"
  40
  41 #if !defined (errno)
  42 extern int errno;
  43 #endif /* !errno */
  44
  45 /* A standard error message to use when getcwd() returns NULL. */
  46 char *bash_getcwd_errstr = "getcwd: cannot access parent directories";
  47
  48 #if !defined (HAVE_SYSCONF) || !defined (_SC_CLK_TCK)
  49 #  if !defined (CLK_TCK)
  50 #    if defined (HZ)
  51 #      define CLK_TCK HZ
  52 #    else
  53 #      define CLK_TCK 60
  54 #    endif
  55 #  endif /* !CLK_TCK */
  56 #endif /* !HAVE_SYSCONF && !_SC_CLK_TCK */
  57
  58 long
  59 get_clk_tck ()
  60 {
  61   static long retval = 0;
  62
  63   if (retval != 0)
  64     return (retval);
  65
  66 #if defined (HAVE_SYSCONF) && defined (_SC_CLK_TCK)
  67   retval = sysconf (_SC_CLK_TCK);
  68 #else /* !SYSCONF || !_SC_CLK_TCK */
  69   retval = CLK_TCK;
  70 #endif /* !SYSCONF || !_SC_CLK_TCK */
  71
  72   return (retval);
  73 }
  74
  75 /* Make the functions strchr and strrchr if they do not exist. */
  76 #if !defined (HAVE_STRCHR)
  77 char *
  78 strchr (string, c)
  79      char *string;
  80      int c;
  81 {
  82   register char *s;
  83
  84   for (s = string; s && *s; s++)
  85     if (*s == c)
  86       return (s);
  87
  88   return ((char *) NULL);
  89 }
  90
  91 char *
  92 strrchr (string, c)
  93      char *string;
  94      int c;
  95 {
  96   register char *s, *t;
  97
  98   for (s = string, t = (char *)NULL; s && *s; s++)
  99     if (*s == c)
 100       t = s;
 101   return (t);
 102 }
 103 #endif /* !HAVE_STRCHR */
 104
 105 #if !defined (HAVE_STRCASECMP)
 106
 107 #if !defined (to_lower)
 108 #  define to_lower(c) (islower(c) ? (c) : toupper(c))
 109 #endif /* to_lower */
 110
 111 /* Compare at most COUNT characters from string1 to string2.  Case
 112    doesn't matter. */
 113 int
 114 strncasecmp (string1, string2, count)
 115      char *string1, *string2;
 116      int count;
 117 {
 118   register char *s1, *s2;
 119   register int r;
 120
 121   if (count > 0)
 122     {
 123       s1 = string1;
 124       s2 = string2;
 125       do
 126         {
 127           if ((r = to_lower (*s1) - to_lower (*s2)) != 0)
 128             return r;
 129           if (*s1++ == '\0')
 130             break;
 131           s2++;
 132         }
 133       while (--count != 0);
 134     }
 135   return (0);
 136 }
 137
 138 /* strcmp (), but caseless. */
 139 int
 140 strcasecmp (string1, string2)
 141      char *string1, *string2;
 142 {
 143   register char *s1, *s2;
 144   register int r;
 145
 146   s1 = string1;
 147   s2 = string2;
 148
 149   while ((r = to_lower (*s1) - to_lower (*s2)) == 0)
 150     {
 151       if (*s1++ == '\0')
 152         return 0;
 153       s2++;
 154     }
 155   return (r);
 156 }
 157 #endif /* !HAVE_STRCASECMP */
 158
 159 /* Return a string corresponding to the error number E.  From
 160    the ANSI C spec. */
 161 #if defined (strerror)
 162 #  undef strerror
 163 #endif
 164
 165 #if !defined (HAVE_STRERROR)
 166 char *
 167 strerror (e)
 168      int e;
 169 {
 170   static char emsg[40];
 171 #if defined (HAVE_SYS_ERRLIST)
 172   extern int sys_nerr;
 173   extern char *sys_errlist[];
 174
 175   if (e > 0 && e < sys_nerr)
 176     return (sys_errlist[e]);
 177   else
 178 #endif /* HAVE_SYS_ERRLIST */
 179     {
 180       sprintf (emsg, "Unknown error %d", e);
 181       return (&emsg[0]);
 182     }
 183 }
 184 #endif /* HAVE_STRERROR */
 185
 186 #if !defined (HAVE_DUP2) || defined (DUP2_BROKEN)
 187 /* Replacement for dup2 (), for those systems which either don't have it,
 188    or supply one with broken behaviour. */
 189 int
 190 dup2 (fd1, fd2)
 191      int fd1, fd2;
 192 {
 193   int saved_errno, r;
 194
 195   /* If FD1 is not a valid file descriptor, then return immediately with
 196      an error. */
 197   if (fcntl (fd1, F_GETFL, 0) == -1)
 198     return (-1);
 199
 200   if (fd2 < 0 || fd2 >= getdtablesize ())
 201     {
 202       errno = EBADF;
 203       return (-1);
 204     }
 205
 206   if (fd1 == fd2)
 207     return (0);
 208
 209   saved_errno = errno;
 210
 211   (void) close (fd2);
 212   r = fcntl (fd1, F_DUPFD, fd2);
 213
 214   if (r >= 0)
 215     errno = saved_errno;
 216   else
 217     if (errno == EINVAL)
 218       errno = EBADF;
 219
 220   /* Force the new file descriptor to remain open across exec () calls. */
 221   SET_OPEN_ON_EXEC (fd2);
 222   return (r);
 223 }
 224 #endif /* !HAVE_DUP2 */
 225
 226 /*
 227  * Return the total number of available file descriptors.
 228  *
 229  * On some systems, like 4.2BSD and its descendents, there is a system call
 230  * that returns the size of the descriptor table: getdtablesize().  There are
 231  * lots of ways to emulate this on non-BSD systems.
 232  *
 233  * On System V.3, this can be obtained via a call to ulimit:
 234  *      return (ulimit(4, 0L));
 235  *
 236  * On other System V systems, NOFILE is defined in /usr/include/sys/param.h
 237  * (this is what we assume below), so we can simply use it:
 238  *      return (NOFILE);
 239  *
 240  * On POSIX systems, there are specific functions for retrieving various
 241  * configuration parameters:
 242  *      return (sysconf(_SC_OPEN_MAX));
 243  *
 244  */
 245
 246 #if !defined (HAVE_GETDTABLESIZE)
 247 int
 248 getdtablesize ()
 249 {
 250 #  if defined (_POSIX_VERSION) && defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
 251   return (sysconf(_SC_OPEN_MAX));       /* Posix systems use sysconf */
 252 #  else /* ! (_POSIX_VERSION && HAVE_SYSCONF && _SC_OPEN_MAX) */
 253 #    if defined (ULIMIT_MAXFDS)
 254   return (ulimit (4, 0L));      /* System V.3 systems use ulimit(4, 0L) */
 255 #    else /* !ULIMIT_MAXFDS */
 256 #      if defined (NOFILE)      /* Other systems use NOFILE */
 257   return (NOFILE);
 258 #      else /* !NOFILE */
 259   return (20);                  /* XXX - traditional value is 20 */
 260 #      endif /* !NOFILE */
 261 #    endif /* !ULIMIT_MAXFDS */
 262 #  endif /* ! (_POSIX_VERSION && _SC_OPEN_MAX) */
 263 }
 264 #endif /* !HAVE_GETDTABLESIZE */
 265
 266 #if !defined (HAVE_BCOPY)
 267 void
 268 bcopy (s,d,n)
 269      char *d, *s;
 270      int n;
 271 {
 272   FASTCOPY (s, d, n);
 273 }
 274 #endif /* !HAVE_BCOPY */
 275
 276 #if !defined (HAVE_BZERO)
 277 void
 278 bzero (s, n)
 279      char *s;
 280      int n;
 281 {
 282   register int i;
 283
 284   for (i = 0; i < n; i++)
 285     s[i] = '\0';
 286 }
 287 #endif
 288
 289 #if !defined (HAVE_GETHOSTNAME)
 290 #  if defined (HAVE_UNAME)
 291 #    include <sys/utsname.h>
 292 int
 293 gethostname (name, namelen)
 294      char *name;
 295      int namelen;
 296 {
 297   int i;
 298   struct utsname ut;
 299
 300   --namelen;
 301
 302   uname (&ut);
 303   i = strlen (ut.nodename) + 1;
 304   strncpy (name, ut.nodename, i < namelen ? i : namelen);
 305   name[namelen] = '\0';
 306   return (0);
 307 }
 308 #  else /* !HAVE_UNAME */
 309 int
 310 gethostname (name, namelen)
 311      int name, namelen;
 312 {
 313   strncpy (name, "unknown", namelen);
 314   name[namelen] = '\0';
 315   return 0;
 316 }
 317 #  endif /* !HAVE_UNAME */
 318 #endif /* !HAVE_GETHOSTNAME */
 319
 320 #if !defined (HAVE_KILLPG)
 321 int
 322 killpg (pgrp, sig)
 323      pid_t pgrp;
 324      int sig;
 325 {
 326   return (kill (-pgrp, sig));
 327 }
 328 #endif /* !HAVE_KILLPG */
 329
 330
 331 /* We supply our own version of getenv () because we want library
 332    routines to get the changed values of exported variables. */
 333
 334 /* The NeXT C library has getenv () defined and used in the same file.
 335    This screws our scheme.  However, Bash will run on the NeXT using
 336    the C library getenv (), since right now the only environment variable
 337    that we care about is HOME, and that is already defined.  */
 338 #if defined (CAN_REDEFINE_GETENV)
 339 static char *last_tempenv_value = (char *)NULL;
 340 extern char **environ;
 341
 342 char *
 343 getenv (name)
 344 #if defined (__linux__) || defined (__bsdi__) || defined (convex)
 345      const char *name;
 346 #else
 347      char const *name;
 348 #endif /* !__linux__ && !__bsdi__ && !convex */
 349 {
 350   SHELL_VAR *var;
 351
 352   var = find_tempenv_variable ((char *)name);
 353   if (var)
 354     {
 355       FREE (last_tempenv_value);
 356
 357       last_tempenv_value = savestring (value_cell (var));
 358       dispose_variable (var);
 359       return (last_tempenv_value);
 360     }
 361   else if (shell_variables)
 362     {
 363       var = find_variable ((char *)name);
 364       if (var && exported_p (var))
 365         return (value_cell (var));
 366     }
 367   else
 368     {
 369       register int i, len;
 370
 371       /* In some cases, s5r3 invokes getenv() before main(); BSD systems
 372          using gprof also exhibit this behavior.  This means that
 373          shell_variables will be 0 when this is invoked.  We look up the
 374          variable in the real environment in that case. */
 375
 376       for (i = 0, len = strlen (name); environ[i]; i++)
 377         {
 378           if ((STREQN (environ[i], name, len)) && (environ[i][len] == '='))
 379             return (environ[i] + len + 1);
 380         }
 381     }
 382
 383   return ((char *)NULL);
 384 }
 385
 386 /* Some versions of Unix use _getenv instead. */
 387 char *
 388 _getenv (name)
 389 #if defined (__linux__) || defined (__bsdi__) || defined (convex)
 390      const char *name;
 391 #else
 392      char const *name;
 393 #endif /* !__linux__ && !__bsdi__ && !convex */
 394 {
 395   return (getenv (name));
 396 }
 397
 398 #endif /* CAN_REDEFINE_GETENV */
 399
 400 #if !defined (HAVE_MKFIFO) && defined (PROCESS_SUBSTITUTION)
 401 int
 402 mkfifo (path, mode)
 403      char *path;
 404      int mode;
 405 {
 406 #if defined (S_IFIFO)
 407   return (mknod (path, (mode | S_IFIFO), 0));
 408 #else /* !S_IFIFO */
 409   return (-1);
 410 #endif /* !S_IFIFO */
 411 }
 412 #endif
 413
 414 #if !defined (HAVE_SETLINEBUF)
 415 /* Cause STREAM to buffer lines as opposed to characters or blocks. */
 416 int
 417 setlinebuf (stream)
 418      FILE *stream;
 419 {
 420 #if defined (_IOLBF)
 421 #  if defined (SETVBUF_REVERSED)
 422   setvbuf (stream, _IOLBF, (char *)NULL, BUFSIZ);
 423 #  else /* !SETVBUF_REVERSED */
 424   setvbuf (stream, (char *)NULL, _IOLBF, BUFSIZ);
 425 #  endif /* !SETVBUF_REVERSED */
 426 #endif /* _IOLBF */
 427   return (0);
 428 }
 429 #endif /* !HAVE_SETLINEBUF */