UNIX for Dummies Questions & Answers

Hi,

I have a script which looks through an input file and takes data from the file to use within the script.

Everything works fine until the script reads the item \windows\directory\structure\ from the input file into a variable.

As unix sees the backslash as an escape character, the variable, when echoed shows windowsdirectorystructure when the literal \windows\directory\structure\ is required.

I tried excaping the escape characters in the input file so that the variable included them, ie putting \\windows\\directory\\structure\\ into the input file. This came back with the same incorrect result too. I also tried \\\windows\\\directory\\\structure\\\ just in case the shell interpreted the variable another time but this showed the same result too.

I also tried using '\windows\directory\structure\' including single quotes in the input file but the variable literally is '\windows\directory\structure\' including single quotes.

If I try assigning the variable on the command line rather than from within the script, I get the desired result. ie

var='\windows\directory\structure\'
echo $var
\windows\directory\structure\

Does anyone have any advice on how I can get the variable in the script to equal \windows\directory\structure\ ?

Many thanks
Helen

If I have a file, say, files.txt

Code:

C:\\path\\to\\first\\windows\\file
C:\\path\\to\\second\\windows\\file

and run the following script against it

Code:

#!/bin/sh

while read var
do
    echo $var
done < files.txt

exit 0

all is well, and the output is:

Code:

$ ./test.sh
C:\path\to\first\windows\file
C:\path\to\second\windows\file

Cheers
ZB

Hi,

The input file I use is slightly different and similar to the following:

field1,field2,field3,C:\\path\\to\\first\\windows\\file,field5
field1,field2,field3,C:\\path\\to\\second\\windows\\file,field5

The script is similar to this:

#!/bin/sh

while read var
do

dir=`echo $var | cut -d , -f 4`
echo $dir

done < files.txt

exit 0

When running it i get:

$test.sh
C:\path o
irst\windows
ile
C:\path o\second\windows
ile
$

Thanks for your help
Helen

Give this a try

Code:

#!/bin/sh
     
while read var
do
     
    dir=`echo $var | cut -d , -f 4 | sed 's/\\\\/\\\\\\\\/g'`
     
    echo $dir
     
done < files.txt
    
exit 0

Change your input file to

Code:

field1,field2,field3,C:\\\\path\\\\to\\\\first\\\\windows\\\\file,field5
field1,field2,field3,C:\\\\path\\\\to\\\\second\\\\windows\\\\file,field5

It's those backslashes that are causing the problem, and need to be sed'ed - and we need to backslash escape the backslashes for each stage of evaluation - and then substitute the correct number of backslash escaped backslashes!

This nightmare only seems to rear it's ugly head under really old original Bourne shells. I've tested my original solution under bash and ksh and it works fine. The original bourne shell on HP-UX (/usr/old/bin/sh) shows this problem, and requires backslash-city as above.

Peace
ZB

Hi ZB

Cool, that works a treat. I'm just glad there isn't a tax on backslashes!! If you're ever around Sheffield, we owe you a drink.

Thanks so much
Helen

If you're using cygwin, it has always let me get away with regular slashes instead of backslashes. Even with "c:/Program Files" and the like.