bash  [options]  [arguments]

    ksh   [options]  [arguments]

               name () {

        function body's code come here

    }

    # fatal --- print an error message and die:



    fatal () {

        echo "$0: fatal error:" "$@" >&2     # messages to standard error

        exit 1

    }

    ...

    if [ $# = 0 ]    # not enough arguments

    then

        fatal not enough arguments

    fi

    function fatal {

        echo "$0: fatal error:" "$@" >&2     # messages to standard error

        exit 1

    }

    cd () {                       Shell function; found before built-in cd

        command cd "$@"           Use real cd to change directory

        echo now in $PWD          Other stuff we want to do

    }

    _cd () {                      Shell function; note leading underscore

        cd "$@"                   Use real cd to change directory

        echo now in $PWD          

$ rpm -q emacs

emacs-21.3-17

up2date [options] [packages]

up2date-nox [options] [packages]

up2date-config

$ grep [A-Z]* chap[12]

            

$ grep Array.c Bug.c Comp.c chap1 chap2

            

$ grep "[A-Z]*" chap[12]

            

emacs [file]

vi [options] file

vi [options] +num file

vi [options] +/pattern file

            

    sed [-n] [-e] 'command' file(s)

    sed [-n]  -f  scriptfile file(s)

            

    [address [,address ]][!]command [arguments]

    $ awk 1 /dev/null

    awk: syntax error near line 1

    awk: bailing out near line 1

    awk  [options]  'script'  var=value  file(s)

    awk  [options]  -f scriptfile  var=value  file(s)

            

               pattern  { action }

    FS = ","

    /widget/ { count["widget"]++ }       Count widgets

    END      { print count["widget"] }   Print the count

            

    for (item in array)

            process array[item]

    if (index in array)

            ...

    # capitalize each word in a string

    function capitalize(input,    result, words, n, i, w)

    {

       result = ""

       n = split(input, words, " ")

       for (i = 1; i <= n; i++) {

            w = words[i]

            w = toupper(substr(w, 1, 1)) substr(w, 2)

            if (i > 1)

                     result = result " "

            result = result w

       }

       return result

    }



    # main program, for testing

    { print capitalize($0) }

    A test line with words and numbers like 12 on it.

    A Test Line With Words And Numbers Like 12 On It.

    mkdir RCS

    ci file

            

    co -l file

            

    ci file

            

    co file

            

    ci -u file

            

    ci -l file

            

    rcsdiff file

            

    cvs [cvs-options] [command] [command-options-and-arguments]

    $Keyword$

    $Keyword: value$

    $ find /tmp/hello -print                  

               Show directory layout

    /tmp/hello

    /tmp/hello/branches                       Directory for branch development

    /tmp/hello/tags                           Directory for tagged releases

    /tmp/hello/trunk

    /tmp/hello/trunk/hello.c                  Mainline development is done on the trunk

    /tmp/hello/trunk/Makefile

    /tmp/hello/trunk/README

    $ svnadmin create /path/to/svnrepos

    $ svn import /tmp/hello file:///path/to/svnrepos -m "initial import"

    Adding         /tmp/hello/trunk

    Adding         /tmp/hello/trunk/hello.c

    Adding         /tmp/hello/trunk/Makefile

    Adding         /tmp/hello/trunk/README

    Adding         /tmp/hello/branches

    Adding         /tmp/hello/tags



    Committed revision 1.

    $ cd                                           

               Move to home directory

    $ svn checkout file:///path/to/svnrepos hello  

               Check out working copy

    A  hello/trunk

    A  hello/trunk/hello.c

    A  hello/trunk/README

    A  hello/trunk/Makefile

    A  hello/branches

    A  hello/tags

    Checked out revision 1.



    $ cd hello/trunk                               

               Change to sandbox

    $ vi message.c hello.c Makefile                

               Make changes

    3 files to edit



    $ cat message.c                                

               Show newly created file

    const char message[  ] = "hello, world!";

    $ make                                         

               Compile program and test it

    cc    -c -o hello.o hello.c

    cc    -c -o message.o message.c

    cc -O hello.o message.o -o hello

    $ 

    svn [options

                

                

] subcommand [arguments]

    make  [options

                

]  [targets]  [macro definitions]

               name=string

            

               name:=string

            

    gdb [options] [executable [corefile-or-PID]]

    gdb [options] --args executable [program args ...]

Since bare troff is unusable by humans, a race of gods now gone created macro packages for mortals to use.

    .TH WHIZPROG 1 "April 1, 2007"

    .SH NAME

    whizprog \- do amazing things

    .SH SYNOPSIS

    .B whizprog

    [

    .I options

    ] [

    .I files

    \&... ]

    .SH DESCRIPTION

    .I Whizprog

    is the next generation of really

    .B cool

    do-it-all programs. ...

    .SH OPTIONS

    .PP

    .I Whizprog

    accepts the following options.

    .TP \w'\fB\-\^\-level\fP'u+3n

    .PD 0

    .B \-h

    .TP

    .PD

    .B \-\^\-help

    Print a helpful message and exit.

    .TP

    .BI \-\^\-level " level"

    Set the level for the

    .B \-\^\-stun

    option.

    .TP

    .B \-\^\-stun

    Stun the competition, or other beings, as needed. ...

    .SH SEE ALSO

    .IR "Whizprog \- The Be All and End All Program" ,

    by J. Programmer.

    .PP

    .IR wimpprog (1)

    .SH FILES

    .B /dev/phaser

    .br

    .B /dev/telepath

    .SH CAVEATS

    .PP

    There are a number of important points to remember.

    .RS

    .IP 1.

    Use

    .B \-\^\-help

    to get help.

    .IP 2.

    Use

    .B \-\^\-stun

    with care.  ...

    .RE

    Forget these at your own risk!

    .SH BUGS

    The

    .B \-\^\-stun

    option currently always uses

    .BR "\-\^\-level 10" ,

    making it rather dangerous.

    .SH AUTHOR

    J. Programmer,

    .B jp@wizard-corp.com