SUMMARY: bug in while-do/done and rsh in shell scripts ????

From: Ken McCoy <kenm_at_apscn.k12.ar.us>
Date: Fri, 09 Jan 1998 09:46:59 +0000

Thanks to all who replied!!

The answer was to put a "-n" on the rsh command.


All replies follow:
============================
You will have to redirect rsh's standard input to /dev/null
i.e.

   rsh xhost ls -al /soft/bin/$line < /dev/null

or use rsh with the -n option. This is no bug. Rsh just uses
up all the input for the loop.

Gerhard

--
 Gerhard Kircher                   kircher_at_edvz.tuwien.ac.at
 Vienna University of Technology   phone: +43 1 588 01 5599
 Computing Services                fax  : +43 1 587 42 11
 Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria
=================================================
I am suspicious of your attempt to pipe the output of "ls" into
the "while" command.  I don't think that will work.  Why not
use the "for" command to run through the output produced by "ls"
and captured by command substitution, e.g.,
 for line
 in `ls`
 do
   rsh xhost ls -al /soft/bin/$line
 done
-Phil Farrell, Computer Systems Manager
Stanford University School of Earth Sciences
farrell_at_pangea.stanford.edu
==============================================
Try the following instead
while LINE in `ls`
do
  rsh xhost ls -al /soft/bin/$LINE
done
Note that since you are using rsh you might need to use the full path
for ls (/usr/bin/ls I believe).
-- 
Thank you,
Andrew Weston
(Network Adminstrator)
 Note: Any comments I may make are not necessarily those of my
 employer.
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===================================================
Try a rsh -n, this is a fix when the remote account is csh
-Stephen
g GE Capital
Information Technology Solutions		WISE  Project
________________________________________________________
Stephen Mullin			phone:_____ (770)300-3373
WISE Project (SAP)		dialcomm:____ 8* 270-3373
GE Capital IT Solutions		fax:________ (770)416-9592
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                                          smullin_at_gecits.ge.com
===================================================
 perhaps, you might try one of these
 for File in *
 do rsh xhost 'ls -al /soft/bin/$File'
 done
 ls -1 > /tmp/tmpfile.$$
 while read line
 do  rsh ...
 done < tmpfile
 rm /tmp/tmpfile.$$
 I might prefer something like...
 #!/usr/bin/ksh
 TmpFile=/tmp/tmp$$
 exec 3< $TmpFile
 while read -u3 line
 do rsh ...
 done
 You probably get several dozen ways of doing this.   It really
depends
 on what you're doing.
 may I ask, are you looking to see if two areas on seperate
systems contain
 identically named files?            If this is the case, then
you might look at
 a tool called rdist or nrdist.
 enjoy,
 /sb
=========================================
Try the -n flag with rsh:
  -n  Redirects any input for rsh to the /dev/null device.  Use this
  flag if
     you are in C shell and run rsh in the background.
I don't know that this will do it, but it's worth a try.  It makes all
the difference in the world in my testing with the Bourne shell
driving the test.  Don't ask how I knew about that flag off the top of
my head..
Tom
 Dr. Thomas P. Blinn, UNIX Software Group, Digital Equipment
 Corporation
  110 Spit Brook Road, MS ZKO3-2/U20   Nashua, New Hampshire
  03062-2698
   Technology Partnership Engineering           Phone:  (603) 884-0646
    Internet: tpb_at_zk3.dec.com           Digital's Easynet: alpha::tpb
     ACM Member: tpblinn_at_acm.org         PC_at_Home: tom_at_felines.mv.net
Thanks
------------------------------------
Ken McCoy
Arkansas Public School Computer Net.

Received on Fri Jan 09 1998 - 16:51:00 NZDT