diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | Doc/Zsh/mod_system.yo | 10 | ||||
| -rw-r--r-- | Src/Modules/system.c | 31 |
3 files changed, 47 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog index 77ab063ad..3b322ecd0 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2010-02-25 Peter Stephenson <pws@csr.com> + + * 27755: Doc/Zsh/mod_system.yo, Src/Modules/system.c: + add "zsystem supports" to test what zsystem supports. + 2010-02-24 Peter Stephenson <p.w.stephenson@ntlworld.com> * 27754: NEWS (unposted), Doc/Zsh/mod_system.yo, Src/exec.c, @@ -12819,5 +12824,5 @@ ***************************************************** * This is used by the shell to define $ZSH_PATCHLEVEL -* $Revision: 1.4914 $ +* $Revision: 1.4915 $ ***************************************************** diff --git a/Doc/Zsh/mod_system.yo b/Doc/Zsh/mod_system.yo index 29047bfe4..dce07175f 100644 --- a/Doc/Zsh/mod_system.yo +++ b/Doc/Zsh/mod_system.yo @@ -148,6 +148,16 @@ If the option tt(-r) is given, the lock is only for reading, otherwise it is for reading and writing. The file descriptor is opened accordingly. ) +item(tt(zsystem supports) var(subcommand))( +The builtin tt(zsystem)'s subcommand tt(supports) tests whether a +given subcommand is supported. It returns status 0 if so, else +status 1. It operates silently unless there was a syntax error +(i.e. the wrong number of arguments), in which case status 255 +is returned. Status 1 can indicate one of two things: var(subcommand) +is known but not supported by the current operating system, or +var(subcommand) is not known (possibly because this is an older +version of the shell before it was implemented). +) enditem() subsect(Parameters) diff --git a/Src/Modules/system.c b/Src/Modules/system.c index ef1ebb0b0..93796128b 100644 --- a/Src/Modules/system.c +++ b/Src/Modules/system.c @@ -491,6 +491,35 @@ bin_zsystem_flock(char *nam, char **args, UNUSED(Options ops), UNUSED(int func)) } +/* + * Return status zero if the zsystem feature is supported, else 1. + * Operates silently for future-proofing. + */ +/**/ +static int +bin_zsystem_supports(char *nam, char **args, + UNUSED(Options ops), UNUSED(int func)) +{ + if (!args[0]) { + zwarnnam(nam, "supports: not enough arguments"); + return 255; + } + if (args[1]) { + zwarnnam(nam, "supports: too many arguments"); + return 255; + } + + /* stupid but logically this should work... */ + if (!strcmp(*args, "supports")) + return 0; +#ifdef HAVE_FCNTL_H + if (!strcmp(*args, "flock")) + return 0; +#endif + return 1; +} + + /**/ static int bin_zsystem(char *nam, char **args, Options ops, int func) @@ -498,6 +527,8 @@ bin_zsystem(char *nam, char **args, Options ops, int func) /* If more commands are implemented, this can be more sophisticated */ if (!strcmp(*args, "flock")) { return bin_zsystem_flock(nam, args+1, ops, func); + } else if (!strcmp(*args, "supports")) { + return bin_zsystem_supports(nam, args+1, ops, func); } zwarnnam(nam, "unknown subcommand: %s", *args); return 1; |