Am 08.01.2018 um 13:56 schrieb Eric Blake: > On 01/07/2018 05:00 AM, Oliver Lange wrote: >> >> Hi everyone, >> >> Just wanted to mention that neither the --help msg nor the man page for >> readlink mention the apparent support for the "--" option to stop >> interpreting further args as possible command options. > > Thanks for the report. However, the use of '--' to end option arguments > is required by POSIX to work for almost ALL applications (not just > coreutils), so we haven't bothered to document it for individual > applications, on the assumption that it is better to document that > behavior at a system-wide level. Any program that uses getopt() will > obey that idiom, so the man page for getopt(3) is such a system-wide place. > > You are correct that the coreutils.info document should mention the > trick up front - and it does, in the "Common options" section 2: > > ‘--help’ > Print a usage message listing all available options, then exit > successfully. > > ‘--version’ > Print the version number, then exit successfully. > > ‘--’ > Delimit the option list. Later arguments, if any, are treated as > operands even if they begin with ‘-’. For example, ‘sort -- -r’ > reads from the file named ‘-r’. > > > I will note that there are a couple of POSIX-based exceptions for > historical reasons; for example, 'echo' must NOT interpret '--' as end > of options, and you are better off using 'printf' than 'echo' if you > need to output a string that starts with a dash. >
Thank you very much for your detailed answer! I suspected that you guys probably had a standard defined somewhere... Maybe this helps someone else, too. Thanks again. -- MfG, Oliver Lange.
