[SOLVED] grep works as commandine but fails as varible

jwilleke · 09-10-2012, 01:58 PM

grep '^Sep 7' /var/log/warn
Works at command line but:

teststr='^Sep 7'
grep ${teststr} /var/log/warn

Fails as it returns all lines which start with Sep.

Any ideas?

Thanks
-jim

colucix · 09-10-2012, 02:03 PM

You have to put double quotes around the variable reference to protect the blank space(s):

Code:

grep "${teststr}" /var/log/warn

otherwise the command results in

Code:

grep ^Sep 7 /var/log/warn

which makes grep to look for the pattern "^Sep" in a file named "7" and in the "/var/log/warn" file.

jwilleke · 09-10-2012, 02:26 PM

That works until it is put in a bash script.
Then it fails to find any entries in the file.

Any ideas?

Thanks

colucix · 09-10-2012, 02:49 PM

Quote:

Originally Posted by jwilleke

Any ideas?

Nope, until you show the current version of your script. Please use CODE tags to embed the lines of code, so that the correct spacing is preserved. I suspect you missed an additional blank space in the pattern, but I can only guess.

In the meanwhile you can compare your code with a working example tested with grep-2.5.4 and bash-4.1.7:

Code:

#!/bin/bash
#
teststr='^Sep  7'
grep "${teststr}" /var/log/warn

YankeePride13 · 09-10-2012, 02:54 PM

Try adding the full path to the grep command in the script as well.

jwilleke · 09-12-2012, 10:45 AM

Thanks.
With your help and fixing some typos and other errors, we did get this to work.

Code:

#!/bin/bash
REPORTDATE='2012-09-07'
YEAR_MONTH=${REPORTDATE%-*}
YEAR=${YEAR_MONTH%-*}
# Month must be like: Sep 9 from 
MONTHSTR=${YEAR_MONTH#*-}
echo $MONTHSTR
DAYSTR=${REPORTDATE##*-}
# Set MONTHSTR to three letter month
MONTHSTR=`date -d 2012/${MONTHSTR}/01 +%b`
# in the war file, there are two spaces for the month number if 0X 
# and only one if 1X
if [[ $DAYSTR == 0* ]]
then
   SPACE='  '
   echo 'Set two spaces'
   # Strip any leading 0 from DAYSTR
   DAYSTR="$(echo $DAYSTR | sed 's/0*//')"
else
   SPACE=' '
   echo 'Set one space'
fi
teststr="^${MONTHSTR}${SPACE}${DAYSTR}"
/usr/bin/grep "${teststr}" /var/log/warn

Thanks!
-jim

YankeePride13 · 09-12-2012, 10:54 AM

No Problem, Jim. Please mark the thread as solved and feel free to give reputation points to those who you found helpful!