GETFLAGS(8) GETFLAGS(8)
NAME
getflags, usage - command-line parsing for shell scripts
SYNOPSIS
aux/getflags $*
aux/usage
DESCRIPTION
Getflags parses the flags in its command-line arguments
according to the environment variable $flagfmt. This vari-
able should be a comma-separated list of flag specifiers.
Each flag is a single letter, optionally followed by a colon
and a name. It may be followed by a space-separated list of
argument names.
Getflags prints an rc(1) script to be evaluated by the call-
ing program. For every flag specified in $flagfmt, the gen-
erated script sets a corresponding environment variable. If
the flag specifier contains :name, the corresponding vari-
able is named $name. Otherwise, it is named $flagx.
After evaluating the script, the environment variables will
be set as follows: If a flag is not present in the argument
list, the environment variable will default to the empty
list. If the flag is present and takes no arguments, the
environment variable will be initialized with the string
'1'. If the flag takes arguments, the flag's variable will
be initialized with a list of those argument values. The
script then sets the variable $* to the list of remaining
non-flag arguments.
The $status is variable to the empty string on success, or
'usage' when there is an error parsing the command line.
Usage prints a usage message to standard error. The message
is constructed using $0, $flagfmt, and $args. The program
name is taken from $0, as set by rc(1) The list of flags is
extracted from $flagfmt. The description of positional
argument list is taken from $args.
EXAMPLE
An example of the script generated:
% flagfmt='e:example, x, a:arg with args'
% aux/getflags -exa arg list positional stuff
example=()
Page 1 Plan 9 (printed 11/18/24)
GETFLAGS(8) GETFLAGS(8)
flagx=()
arg=()
example=1
flagx=1
arg=(arg list)
*=(positional stuff)
status=''
Parse the arguments for leak(1):
flagfmt='b:showbmp, s:acidfmt, f binary, r res, x width'
args='name | pid list'
if(! ifs=() eval `{aux/getflags $*} || ~ $#* 0){
aux/usage
exit usage
}
if(~ $#showbmp 0)
echo '-b flag not set'
echo $showbmp # named
echo $acidfmt # also named
echo $flagf # default name
echo $flagr # default name
SOURCE
/sys/src/cmd/aux/getflags.c
/sys/src/cmd/aux/usage.c
SEE ALSO
arg(2)
Page 2 Plan 9 (printed 11/18/24)