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Old 05-04-2009, 04:05 PM   #1
vxc69
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csh Shell Script: Getting wc command output to variable to do math on it, how?


Hello guys,


A quick CSH question. I'm trying to run wc -l on a file. I want to get this line count on to a variable in my csh script. I'm not doing it right.

This is what i've tried to no avail:

Code:
1.) set numlinks = `cat` $file | wc -l
2.) numlinks = `cat` $file | wc -l
$file comes from a foreach loop. $file is ok because if I just run 'cat' $file | wc -l, it prints out the correct amount of lines.

Once I get this count into a variable I want to do some arithmetic on it. First time writing shell scripts by the way, so excuse my ignorance.



Thanks for any help,
vxc

Last edited by vxc69; 05-04-2009 at 04:08 PM.
 
Old 05-04-2009, 04:17 PM   #2
colucix
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Your commands don't work because you put backticks around the cat command only, whereas you have to embed the whole command line:
Code:
set numlinks = `cat $file | wc -l`
Then use expr to do arithmetic:
Code:
set numlinks = `expr $numlinks + 1`
Hope this helps.
 
Old 05-04-2009, 04:17 PM   #3
Eycks
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numlinks = <back quote>cat $file | wc -l<back quote>

My <back quote> key does not work. If this does not work try putting set in fron of numlinks
 
Old 05-04-2009, 04:22 PM   #4
vxc69
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Quote:
Originally Posted by colucix View Post
Your commands don't work because you put backticks around the cat command only, whereas you have to embed the whole command line:
Code:
set numlinks = `cat $file | wc -l`
Then use expr to do arithmetic:
Code:
set numlinks = `expr $numlinks + 1`
Hope this helps.
Oh! I thought that it would try to cat $file instead of what's in $file if i put that in back quotes too. Putting the entire thing in back quotes worked! Thanks. Well appreciated.
 
Old 05-04-2009, 04:27 PM   #5
raconteur
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Enclose the whole command in back quotes, and make sure your variable assignments don't have spaces around the equals signs.

For example:
Code:
foreach file (your_list)
  set numlinks=`cat $file | wc -l`
  echo "numlinks for $file is $numlinks"
end
hth

Last edited by raconteur; 05-04-2009 at 04:28 PM. Reason: beaten to the punch while composing ;-)
 
Old 05-04-2009, 04:31 PM   #6
colucix
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Quote:
Originally Posted by raconteur View Post
and make sure your variable assignments don't have spaces around the equals signs.
Not strictly necessary in C-shells. That's true for Bourne-shells instead.
 
  


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