What is the difference between the following two commands, when run on AIX?
/bin/sh 'ls -l -R'
/bin/sh -c 'ls -l -R'
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439answers:
2
+7
A:
On AIX, /bin/sh defaults to the Korn Shell (ksh).
/bin/sh 'ls -l -R'
With ksh, this runs the shell, telling it to execute the script named ls -l -R (in the current directory or on the path). If no script can be found with this name, ksh treats the argument as a command and runs it.
Note that with bash, if the script cannot be found, this would result in an error.
/bin/sh -c 'ls -l -R'
This starts a new instance of the shell, telling it to run the command ls -l -R.
Phil Ross
2010-03-23 14:10:24
>/bin/sh 'ls -l -R' total 80 -rw-rw---- 1 user user 39301 Mar 22 18:17 db.trace
Vladimir Bezugliy
2010-03-23 14:48:06
I do not have any problems with the command /bin/sh 'ls -l -R'
Vladimir Bezugliy
2010-03-23 14:57:33
@Vladimir: Then you have different version of sh. On my system, the above command results in: `/bin/sh: Can't open ls -l -R`. What does `ls -l /bin/sh` show on your system?
Heinzi
2010-03-23 15:41:48
>ls -l /bin/sh-r-xr-xr-x 5 bin bin 246558 Sep 20 2008 /bin/sh
Vladimir Bezugliy
2010-03-23 16:12:03
@Vladimir What is the result of running `/bin/sh --version`?
Phil Ross
2010-03-23 16:24:55
$ /bin/sh --version--version: bad option(s)
Vladimir Bezugliy
2010-03-23 16:31:58
It is AIX not Linux.
Vladimir Bezugliy
2010-03-23 16:32:14
@Vladimir Since, you are using AIX, `sh` is probably the Korn shell (ksh). I've updated my answer.
Phil Ross
2010-03-23 17:13:38
+4
A:
(This is in response to Phil Ross, but I need formatting:)
Using one of my Linux accounts:
sh> /bin/sh --version
GNU bash, version 3.2.39(1)-release (i386-redhat-linux-gnu)
Copyright (C) 2007 Free Software Foundation, Inc.
sh> /bin/sh 'ls -l -R'
/bin/sh: ls -l -R: No such file or directory
sh> /bin/sh ls
/bin/ls: /bin/ls: cannot execute binary file
sh> /bin/sh -c 'ls -l | head -1'
total 147296
sh>
Using one of my Cygwin installations:
sh> /bin/sh --version
GNU bash, version 3.2.49(23)-release (i686-pc-cygwin)
Copyright (C) 2007 Free Software Foundation, Inc.
sh> /bin/sh 'ls -l -R'
/bin/sh: ls -l -R: No such file or directory
sh> /bin/sh ls
/usr/bin/ls: /usr/bin/ls: cannot execute binary file
sh> /bin/sh -c 'ls -l | head -1'
total 264744
sh>
Your sh may vary, but this appears to be the appropriate behaviour:
- supplying a filename argument to /bin/sh will interpret it as the filename of a shell script and try to execute it
- supplying -c with an argument will interpret that argument as a /bin/sh command line and try to execute that
For more details, type
man sh
reinierpost
2010-03-23 15:48:54