GETOPT(1) | General Commands Manual | GETOPT(1) |
args=̀getopt optstring $*̀
set -- ̀getopt optstring $*̀
getopt should not be used in new scripts; use the shell builtin getopts instead.
args=̀getopt abc: $*̀ if [ $? -ne 0 ]; then echo 'Usage: ...' exit 2 fi set -- $args while [ $# -gt 0 ]; do case "$1" in -a|-b) flag=$1 ;; -c) carg=$2; shift ;; --) shift; break ;; esac shift done
This code will accept any of the following as equivalent:
cmd -acarg file file cmd -a -c arg file file cmd -carg -a file file cmd -a -carg -- file file
IEEE Std 1003.2 (“POSIX.2”) mandates that the sh(1) set command return the value of 0 for the exit status. Therefore, the exit status of the getopt command is lost when getopt and the sh(1) set command are used on the same line. The example given is one way to detect errors found by getopt.
Arguments containing white space or embedded shell metacharacters generally will not survive intact; this looks easy to fix but isn't.
The error message for an invalid option is identified as coming from getopt rather than from the shell procedure containing the invocation of getopt; this again is hard to fix.
The precise best way to use the set command to set the arguments without disrupting the value(s) of shell options varies from one shell version to another.
November 28, 2009 | NetBSD 6.1 |