Return to getopt.1 CVS log

Up to [local] / src / usr.bin / getopt

Annotation of src/usr.bin/getopt/getopt.1, Revision 1.12

1.12    ! otto        1: .\"    $OpenBSD: getopt.1,v 1.11 2006/01/14 09:37:24 jmc Exp $ -*- nroff -*-
1.8       jmc         2: .\"
                      3: .\" This material, written by Henry Spencer, was released by him
                      4: .\" into the public domain and is thus not subject to any copyright.
                      5: .\"
1.1       deraadt     6: .Dd June 21, 1993
                      7: .Dt GETOPT 1
                      8: .Os
                      9: .Sh NAME
                     10: .Nm getopt
                     11: .Nd parse command options
                     12: .Sh SYNOPSIS
1.10      jmc        13: .Nm args=`getopt optstring $*`; errcode=$?; set -- $args
1.1       deraadt    14: .Sh DESCRIPTION
1.4       aaron      15: .Nm
1.1       deraadt    16: is used to break up options in command lines for easy parsing by
                     17: shell procedures, and to check for legal options.
1.4       aaron      18: .Op optstring
1.1       deraadt    19: is a string of recognized option letters (see
1.7       aaron      20: .Xr getopt 3 ) ;
1.1       deraadt    21: if a letter is followed by a colon, the option
                     22: is expected to have an argument which may or may not be
1.5       aaron      23: separated from it by whitespace.
1.1       deraadt    24: The special option
1.9       jmc        25: .Sq --
1.1       deraadt    26: is used to delimit the end of the options.
1.4       aaron      27: .Nm
1.1       deraadt    28: will place
1.9       jmc        29: .Sq --
1.1       deraadt    30: in the arguments at the end of the options,
                     31: or recognize it if used explicitly.
                     32: The shell arguments
1.9       jmc        33: .Pf ( Va $1 , $2 , ... )
                     34: are reset so that each option is
1.1       deraadt    35: preceded by a
1.9       jmc        36: .Sq -
1.1       deraadt    37: and in its own shell argument;
                     38: each option argument is also in its own shell argument.
1.11      jmc        39: .Pp
                     40: Note that the construction
                     41: .Cm set -- `getopt optstring $*`
                     42: is not recommended,
                     43: as the exit value from
                     44: .Dq set
                     45: will prevent the exit value from
                     46: .Nm
                     47: from being determined.
1.6       aaron      48: .Sh EXAMPLES
1.1       deraadt    49: The following code fragment shows how one might process the arguments
                     50: for a command that can take the options
1.6       aaron      51: .Fl a
1.1       deraadt    52: and
1.6       aaron      53: .Fl b ,
1.1       deraadt    54: and the option
1.6       aaron      55: .Fl o ,
1.1       deraadt    56: which requires an argument.
                     57: .Bd -literal -offset indent
1.10      jmc        58: args=`getopt abo: $*`
                     59: if [ $? -ne 0 ]
1.1       deraadt    60: then
                     61:        echo 'Usage: ...'
                     62:        exit 2
                     63: fi
1.10      jmc        64: set -- $args
1.12    ! otto       65: while [ $# -ge 0 ]
1.1       deraadt    66: do
1.12    ! otto       67:        case "$1"
1.1       deraadt    68:        in
1.9       jmc        69:                -a|-b)
1.12    ! otto       70:                        flag="$1"; shift;;
1.9       jmc        71:                -o)
1.12    ! otto       72:                        oarg="$2"; shift; shift;;
1.9       jmc        73:                --)
1.1       deraadt    74:                        shift; break;;
                     75:        esac
                     76: done
                     77: .Ed
                     78: .Pp
                     79: This code will accept any of the following as equivalent:
                     80: .Bd -literal -offset indent
1.9       jmc        81: cmd -aoarg file file
                     82: cmd -a -o arg file file
                     83: cmd -oarg -a file file
                     84: cmd -a -oarg -- file file
1.1       deraadt    85: .Ed
                     86: .Sh DIAGNOSTICS
1.4       aaron      87: .Nm
1.1       deraadt    88: prints an error message on the standard error output when it
                     89: encounters an option letter not included in
                     90: .Op optstring .
1.6       aaron      91: .Sh SEE ALSO
                     92: .Xr sh 1 ,
                     93: .Xr getopt 3
1.1       deraadt    94: .Sh HISTORY
                     95: Written by Henry Spencer, working from a Bell Labs manual page.
                     96: Behavior believed identical to the Bell version.
                     97: .Sh BUGS
                     98: Whatever
                     99: .Xr getopt 3
                    100: has.
                    101: .Pp
1.5       aaron     102: Arguments containing whitespace or embedded shell metacharacters
1.6       aaron     103: generally will not survive intact; this looks easy to fix but isn't.
1.1       deraadt   104: .Pp
                    105: The error message for an invalid option is identified as coming
                    106: from
1.4       aaron     107: .Nm
1.1       deraadt   108: rather than from the shell procedure containing the invocation
                    109: of
                    110: .Nm getopt ;
                    111: this again is hard to fix.
                    112: .Pp
                    113: The precise best way to use the
                    114: .Nm set
                    115: command to set the arguments without disrupting the value(s) of
                    116: shell options varies from one shell version to another.