[prog] bash: string comparisons in conditionals
riccarda.cassini at gmx.de
Fri Apr 23 14:46:24 EST 2004
Conor Daly wrote:
> AIUI, test is not a bash builtin;
> [cdaly at bofh cdaly]$ which [
> [cdaly at bofh cdaly]$ ls -l /usr/bin/[
> lrwxrwxrwx 1 root root 4 Nov 4 11:56 /usr/bin/[ -> test
> Since you're calling 'test' as '[', should you be looking for '[' in
> strace's output rather than 'test'? I don't know, just wondering.
Actually, I did try both variants... same result: no trace of 'test'
or '[' whatsoever (also no exec*() other than the main script...).
But what's that /usr/bin/[ then for? Hm... maybe for some other
Another question that just occurred to me: is there any difference
whether I write 'test' (for example) on the interactive commandline,
or stick it into some shell script (that I run via #!/bin/sh). Or,
put differently, is a builtin always treated as a builtin, even on the
commandline, or would I interactively run some corresponding binary,
if one is found along the search path for executables? Hmm, hope you
understand what I mean... (I guess I can force the binary to be run
by writing /usr/bin/test, but what about plain 'test'?)
...got to do some 'real' work now (java-GUI) - unfortunately, I'm
currently not being paid for doing investigations of this sort... ;-)
Will carry on with this as soon as I get around to it in the evening.
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