Re: Wilcards in Linux

[Tero Koskinen <tero.koskinen@iki.fi>]

Ludovic Brenta kirjoitti:
> This documents the "Shell Command Language" so does not apply to
> programs that want to process the wildcards themselves. The reason why
> it is so easy to mistakenly assume that this globbing grammar applies
> to all programs is because, on Unix, programs do not normally expand
> any wildcards; the shell does that and passes the expanded file names
> to the programs.

Mr. Brenta is right in here. The filename expansion is handled by
unix shells and is called "globbing". The behaviour can be controlled
via shells' options or environment variables, so it _depends_ on
the used shell.

For example in zsh:
> $ mkdir example
> $ cd example
> $ touch a.c b.c .c
> $ ls -lA
> total 0
> -rw-r--r--  1 tkoskine  tkoskine  0 Aug 14 21:05 .c
> -rw-r--r--  1 tkoskine  tkoskine  0 Aug 14 21:05 a.c
> -rw-r--r--  1 tkoskine  tkoskine  0 Aug 14 21:05 b.c
> $ ls *.c
> a.c b.c
> $ setopt NO_GLOB
> $ ls *.c
> ls: *.c: No such file or directory
> $ setopt GLOB;setopt GLOB_DOTS
> $ ls *.c
> .c  a.c b.c
> $ setopt NULL_GLOB;setopt GLOB
> $ setopt NO_GLOB_DOTS
> $ ls -a *.c
> a.c b.c
> $ ls *.c
> a.c b.c
> $ touch d.ada
> $ ls *.pascal
> a.c   b.c   d.ada
> $

Notice how "ls *.pascal" lists those *.c and *.ada files!

-Tero Koskinen