.\" the source, must acknowledge the copyright and authors of this work.
.\" %%%LICENSE_END
.\"
-.\" 2007-10-23 mtk Added intro paragraph about section, plus a paragraph
-.\" about exit status values.
-.\"
-.TH INTRO 1 2007-11-15 "Linux" "Linux User's Manual"
+.TH INTRO 1 2015-07-23 "Linux" "Linux User's Manual"
.SH NAME
intro \- introduction to user commands
.SH DESCRIPTION
Section 1 of the manual describes user commands and tools,
for example, file manipulation tools, shells, compilers,
web browsers, file and image viewers and editors, and so on.
-
-All commands yield a status value on termination.
-This value can be tested (e.g., in most shells the variable
-.I $?
-contains the status of the last executed command)
-to see whether the command completed successfully.
-A zero exit status is conventionally used to indicate success,
-and a nonzero status means that the command was unsuccessful.
-(Details of the exit status can be found in
-.BR wait (2).)
-A nonzero exit status can be in the range 1 to 255, and some commands
-use different nonzero status values to indicate the reason why the
-command failed.
.SH NOTES
Linux is a flavor of UNIX, and as a first approximation
all user commands under UNIX work precisely the same under
Linux (and FreeBSD and lots of other UNIX-like systems).
-.LP
+.PP
Under Linux, there are GUIs (graphical user interfaces), where you
can point and click and drag, and hopefully get work done without
first reading lots of documentation.
but requires finding out what the commands are.
Below a bare minimum, to get started.
.SS Login
-In order to start working, you probably first have to login,
-that is, give your username and password.
-See also
-.BR login (1).
+In order to start working, you probably first have to open a session by
+giving your username and password.
The program
-.I login
+.BR login (1)
now starts a
.I shell
(command interpreter) for you.
the command interpreter.
It is not built-in, but is just a program
and you can change your shell.
-Everybody has her own favorite one.
+Everybody has their own favorite one.
The standard one is called
.IR sh .
See also
.BR ash (1),
.BR bash (1),
+.BR chsh (1),
.BR csh (1),
-.BR zsh (1),
-.BR chsh (1).
-.LP
-A session might go like
-
-.RS
-.nf
+.BR dash (1),
+.BR ksh (1),
+.BR zsh (1).
+.PP
+A session might go like:
+.PP
+.in +4n
+.EX
.RB "knuth login: " aeb
.RB "Password: " ********
-.RB "% " date
+.RB "$ " date
Tue Aug 6 23:50:44 CEST 2002
-.RB "% " cal
+.RB "$ " cal
August 2002
Su Mo Tu We Th Fr Sa
1 2 3
18 19 20 21 22 23 24
25 26 27 28 29 30 31
-.RB "% " ls
+.RB "$ " ls
bin tel
-.RB "% " "ls \-l"
+.RB "$ " "ls \-l"
total 2
drwxrwxr\-x 2 aeb 1024 Aug 6 23:51 bin
\-rw\-rw\-r\-\- 1 aeb 37 Aug 6 23:52 tel
-.RB "% " "cat tel"
+.RB "$ " "cat tel"
maja 0501\-1136285
peter 0136\-7399214
-.RB "% " "cp tel tel2"
-.RB "% " "ls \-l"
+.RB "$ " "cp tel tel2"
+.RB "$ " "ls \-l"
total 3
drwxr\-xr\-x 2 aeb 1024 Aug 6 23:51 bin
\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:52 tel
\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:53 tel2
-.RB "% " "mv tel tel1"
-.RB "% " "ls \-l"
+.RB "$ " "mv tel tel1"
+.RB "$ " "ls \-l"
total 3
drwxr\-xr\-x 2 aeb 1024 Aug 6 23:51 bin
\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:52 tel1
\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:53 tel2
-.RB "% " "diff tel1 tel2"
-.RB "% " "rm tel1"
-.RB "% " "grep maja tel2"
+.RB "$ " "diff tel1 tel2"
+.RB "$ " "rm tel1"
+.RB "$ " "grep maja tel2"
maja 0501\-1136285
-%
-.fi
-.RE
-and here typing Control-D ended the session.
+$
+.EE
+.in
+.PP
+Here typing Control-D ended the session.
+.PP
The
-.B "% "
+.B $
here was the command prompt\(emit is the shell's way of indicating
that it is ready for the next command.
The prompt can be customized
machine name, current directory, time, and so on.
An assignment PS1="What next, master? "
would change the prompt as indicated.
-.LP
+.PP
We see that there are commands
.I date
(that gives date and time), and
.I cal
(that gives a calendar).
-.LP
+.PP
The command
.I ls
lists the contents of the current directory\(emit tells you what
.I chown
and
.IR chmod .
-.LP
+.PP
The command
.I cat
will show the contents of a file.
(The name is from "concatenate and print": all files given as
-parameters are concatenated and sent to "standard output", here
+parameters are concatenated and sent to "standard output"
+(see
+.BR stdout (3)),
+here
the terminal screen.)
-.LP
+.PP
The command
.I cp
(from "copy") will copy a file.
-On the other hand, the command
+.PP
+The command
.I mv
-(from "move") only renames it.
-.LP
+(from "move"), on the other hand, only renames it.
+.PP
The command
.I diff
lists the differences between two files.
Here there was no output because there were no differences.
-.LP
+.PP
The command
.I rm
(from "remove") deletes the file, and be careful! it is gone.
No wastepaper basket or anything.
Deleted means lost.
-.LP
+.PP
The command
.I grep
(from "g/re/p") finds occurrences of a string in one or more files.
Files live in a large tree, the file hierarchy.
Each has a
.I "pathname"
-describing the path from the root of the tree (which is called /)
+describing the path from the root of the tree (which is called
+.IR / )
to the file.
-For example, such a full pathname might be /home/aeb/tel.
+For example, such a full pathname might be
+.IR /home/aeb/tel .
Always using full pathnames would be inconvenient, and the name
of a file in the current directory may be abbreviated by giving
only the last component.
-That is why "/home/aeb/tel" can be abbreviated
-to "tel" when the current directory is "/home/aeb".
-.LP
+That is why
+.I /home/aeb/tel
+can be abbreviated
+to
+.I tel
+when the current directory is
+.IR /home/aeb .
+.PP
The command
.I pwd
prints the current directory.
-.LP
+.PP
The command
.I cd
changes the current directory.
-Try "cd /" and "pwd" and "cd" and "pwd".
+.PP
+Try alternatively
+.I cd
+and
+.I pwd
+commands and explore
+.I cd
+usage: "cd", "cd .", "cd ..", "cd /" and "cd ~".
.SS Directories
The command
.I mkdir
makes a new directory.
-.LP
+.PP
The command
.I rmdir
removes a directory if it is empty, and complains otherwise.
-.LP
+.PP
The command
.I find
(with a rather baroque syntax) will find files with given name
or other properties.
For example, "find . \-name tel" would find
-the file "tel" starting in the present directory (which is called ".").
+the file
+.I tel
+starting in the present directory (which is called
+.IR . ).
And "find / \-name tel" would do the same, but starting at the root
of the tree.
Large searches on a multi-GB disk will be time-consuming,
usually
.IR less .
Hit the space bar to get the next page, hit q to quit.
-.LP
+.PP
In documentation it is customary to refer to man pages
by giving the name and section number, as in
.BR man (1).
detail.
For newcomers an introductory text with more examples
and explanations is useful.
-.LP
+.PP
A lot of GNU/FSF software is provided with info files.
Type "info info"
-for an introduction on the use of the program "info".
-.LP
+for an introduction on the use of the program
+.IR info .
+.PP
Special topics are often treated in HOWTOs.
Look in
.I /usr/share/doc/howto/en
.\" Actual examples? Separate section for each of cat, cp, ...?
.\" gzip, bzip2, tar, rpm
.SH SEE ALSO
-.BR ash (1),
+.BR ash (1),
.BR bash (1),
.BR chsh (1),
-.BR csh (1),
-.BR locate (1),
+.BR csh (1),
+.BR dash (1),
+.BR ksh (1),
+.BR locate (1),
.BR login (1),
.BR man (1),
.BR xterm (1),
-.BR zsh(1),
+.BR zsh (1),
.BR wait (2),
+.BR stdout (3),
.BR man-pages (7),
.BR standards (7)
projects / thirdparty / man-pages.git / blobdiff