Comments on: Bash bracket hacking http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/ Your blog is probably better than mine. Sun, 05 Feb 2012 05:18:10 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: TheBonsai http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-96168 TheBonsai Thu, 24 Dec 2009 14:03:01 +0000 http://thesmithfam.org/blog/?p=188#comment-96168 I'm sorry for the delay :) @Dave It's just that your external [ is fault tolerant. I’m sorry for the delay :)

@Dave

It’s just that your external [ is fault tolerant.

]]> By: Dave http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-93972 Dave Fri, 27 Nov 2009 23:59:10 +0000 http://thesmithfam.org/blog/?p=188#comment-93972 @TheBonsai: I'll explain with an example: Run this (this uses the binary, you might need /usr/bin instead of /bin on your system): /bin/[ 42 -gt 43 And it works as expected even though it's missing the closing bracket. Now run this (this uses the built-in): [ 42 -gt 43 -bash: [: missing `]' The built-in wants the closing bracket, but the [ binary doesn't care. @TheBonsai:

I’ll explain with an example:

Run this (this uses the binary, you might need /usr/bin instead of /bin on your system):

/bin/[ 42 -gt 43

And it works as expected even though it's missing the closing bracket.

Now run this (this uses the built-in):

[ 42 -gt 43
-bash: [: missing `]‘

The built-in wants the closing bracket, but the [ binary doesn’t care.

]]> By: TheBonsai http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-93958 TheBonsai Fri, 27 Nov 2009 22:55:50 +0000 http://thesmithfam.org/blog/?p=188#comment-93958 @Byron: It's not a problem to disable those builtins or to explicit call the external code. Since not every shell might have them builtin, but POSIX actually requires the behaviour and the command names, they're usually present as binaries on disk (doesn't apply to binaries you can only implement as a builtin, of course, except the cd command maybe). @Dave: I don't really understand that. Code? @Byron:

It’s not a problem to disable those builtins or to explicit call the external code. Since not every shell might have them builtin, but POSIX actually requires the behaviour and the command names, they’re usually present as binaries on disk (doesn’t apply to binaries you can only implement as a builtin, of course, except the cd command maybe).

@Dave:

I don’t really understand that. Code?

]]> By: harold http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-79442 harold Wed, 03 Jun 2009 14:19:03 +0000 http://thesmithfam.org/blog/?p=188#comment-79442 You may also use type -P instead of which! help type type -a [ type -p [ type -P [ help test see: http://codesnippets.joyent.com/posts/show/2067 You may also use type -P instead of which!

help type

type -a [
type -p [
type -P [

help test

see: http://codesnippets.joyent.com/posts/show/2067

]]> By: Dave http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-75965 Dave Sun, 12 Apr 2009 12:56:08 +0000 http://thesmithfam.org/blog/?p=188#comment-75965 Ah, very nice. This makes sense, because when using '[' on the command line for a one-liner, you don't have to include the closing ']', but in a bash script, you do. I guess that proves Byron's point. --Dave Ah, very nice. This makes sense, because when using ‘[' on the command line for a one-liner, you don't have to include the closing ']‘, but in a bash script, you do. I guess that proves Byron’s point.

–Dave

]]> By: Byron Clark http://thesmithfam.org/blog/2009/04/11/bash-bracket-hacking/comment-page-1/#comment-75964 Byron Clark Sun, 12 Apr 2009 12:49:48 +0000 http://thesmithfam.org/blog/?p=188#comment-75964 Actually, when writing a bash script, both '[' and 'test' are shell builtins so the /usr/bin versions are not used. Actually, when writing a bash script, both ‘[‘ and ‘test’ are shell builtins so the /usr/bin versions are not used.

]]>