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Say I have an executable (running on mac, win, and linux)
a.out [-a] [-b] [-r -i <file> -o <file> -t <double> -n <int> ]
where an argument in [ ] means that it is optional. However, if the last argument -r is set then -i,-o,-t, and -n have to be supplied, too.
There are lots of good C++-libraries out there to parse command-line arguments, e.g. gflags (http://code.google.com/p/gflags/), tclap (http://tclap.sourceforge.net/), simpleopt(http://code.jellycan.com/simpleopt/), boost.program_options (http://www.boost.org/doc/libs/1_52_0/doc/html/program_options.html), etc. But I wondered if there is one that lets me encode these conditional relationships between arguments directly, w/o manually coding error handling
if ( argR.isSet() && ( ! argI.isSet() || ! argO.isSet() || ... ) ) ...
and manually setting up the --help.
The library tclap allows to XOR arguments, e.g. either -a or -b is allowed but not both. So, in that terminology an AND for arguments would be nice.
Does anybody know a versatile, light-weight, and cross-platform library that can do that?
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We can use the getopts program/ command to parse the arguments passed to the script in the command line/ terminal by using loops and switch-case statements. Using getopts, we can assign the positional arguments/ parameters from the command line to the bash variables directly.
The special character $# stores the total number of arguments. We also have $@ and $* as wildcard characters which are used to denote all the arguments. We use $$ to find the process ID of the current shell script, while $? can be used to print the exit code for our script.
You can handle command-line arguments in a bash script in two ways. One is by using argument variables, and another is by using the getopts function.
You could two passes over the arguments; If -r is in the options you reset the parser and start over with the new mandatory options added.
You could also look into how the TCLAP XorHandler works, and create your own AndHandler.
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