Re: rm -- -b
Jim Meyering wrote: Peter Hans van den Muijzenberg wrote: Am I to understand that the coreutils all accept an option --, for end of options, but that neither the --help, nor the man, nor the info document this? Depends on where you look. With the latest pre-6.10 coreutils, I see this example: This has been in the code for long before 6.x and by looking in the source (with git whatchanged -p -S'rm -- -foo' src/rm.c) shows that this was added in May 2000. So this has been around for a long time and would also be in quite older fileutils versions 4.x long before coreutils 6.10. But the real reason I wanted to say something was to talk about the paradigm of '--' and options. This is common behavior to a whole class of programs that parse options and is therefore useful in general to know about. The rigorous place to start is with the getopt(3) man page where it documents the format of the command line parsed by it but in summary '--' ends the left to right across the argument list processing of command line options. A scan is made left to right across the argument list looking for options. Traditional behavior and POSIX require options before non-option arguments. As a GNU extension options may appear anywhere in the argument list. If a -- is encountered it is taken as the end of option processing. Any arguments that follow will not be parsed as a option. Because all of the programs that use getopt follow this convention it is good one to know for shell programming. Almost all of the programs that are used in shell programming such as rm, mv, cp, grep, sed, cat, etc. all use getopt for option processing and all behave the same way with respect to option processing. This is so fundamental that it almost can't be documented in each program because it would be replicated in almost every documentation page. This behavior is what I expect to see from every program and am disappointed when it is not the behavior. Bob ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: rm -- -b
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 Bob Proulx wrote: A scan is made left to right across the argument list looking for options. Traditional behavior and POSIX require options before non-option arguments. As a GNU extension options may appear anywhere in the argument list. If a -- is encountered it is taken as the end of option processing. Any arguments that follow will not be parsed as a option. Because all of the programs that use getopt follow this convention it is good one to know for shell programming. Almost all of the programs that are used in shell programming such as rm, mv, cp, grep, sed, cat, etc. all use getopt for option processing and all behave the same way with respect to option processing. This is so fundamental that it almost can't be documented in each program because it would be replicated in almost every documentation page. This behavior is what I expect to see from every program and am disappointed when it is not the behavior. POSIX also has it in its Utility Conventions, and both requires this behavior of its core utilities, and recommends their use by authors of other utilities. Even though POSIX requires all options be specified before non-option arguments, it is still useful for cases such as the one in this thread's Subject. :) - -- Micah J. Cowan Programmer, musician, typesetting enthusiast, gamer... http://micah.cowan.name/ -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHAJrF7M8hyUobTrERCGvcAJ92Ebybppp6Sy7L9zg4bWEqIXR6rQCffE4q /V3CWb/h9chQgy1OwH1Orr4= =dAcl -END PGP SIGNATURE- ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: rm -- -b
Peter Hans van den Muijzenberg [EMAIL PROTECTED] wrote: Hi, Am I to understand that the coreutils all accept an option --, for end of options, but that neither the --help, nor the man, nor the info document this? Depends on where you look. With the latest pre-6.10 coreutils, I see this example: $ rm --help|grep -B2 rm.-- To remove a file whose name starts with a `-', for example `-foo', use one of these commands: rm -- -foo It is mentioned in coreutils.info, too. ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
