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Old 12-06-2012, 10:02 AM   #1
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sed command using variable

Hi All,

I am trying to run a sed command to add a variable to certain position on a line of a file.

file is below (trailerfile)

TOT_______________________________________________________________________________________________To tal EUR0000000000001568.50

i have a variable called total which is already defined as a numeric value (0000000000001582.18)

the command im using is:
sed 's:\(.\{107\}\)\(.\{19\}\):\1$total:' trailerfile

but its returning:
TOT_______________________________________________________________________________________________To tal EUR$total

any advice how to make 0000000000001582.18 appear instead of $total?

Last edited by nwalsh88; 12-06-2012 at 10:07 AM.
Old 12-06-2012, 10:11 AM   #2
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Using single quotes will tell the shell not to expand the variable.

2 solutions: use double quotes:
sed "s/\(.*EUR\).*/\1$total/" infile
or using single quotes:
sed 's/\(.*EUR\).*/\1'$total'/' infile
Old 12-06-2012, 02:53 PM   #3
David the H.
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1) Please use ***[code][/code]*** tags around your code and data, to preserve the original formatting and to improve readability. Do not use quote tags, bolding, colors, "start/end" lines, or other creative techniques.

The long, unbroken lines in your post are forcing my screen to side-scroll. Edit it to enclose them, please.

2) Please try doing a search of past threads first. Questions like this tend to come up with good regularity.

In any case, this is a common example of how important it is to understand the shell's quoting behavior and argument parsing.

3) You can avoid most of those backslashes if you enable the -r extended regular expressions option.

sed -r "s:(.{107})(.{19}):\1$total:" trailerfile
See the section on basic versus extended regex in the sed info page.


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