Grep Limit

How about:
cut -c1-200 filename |grep pattern

The obvious problem is that it will only return the truncated line...but you could use the first pass to generate the a list of matching line numbers and a second pass to extract those (complete) lines, e.g.

for LINE in `grep -n 1 filename | awk -F: '{printf $1 " "}'`
do
  sed -n -s ${LINE}p filename
done

But that would be inefficient for large files, so maybe use awk instead...

awk '{if ( substr($0,1,200) ~ "PATTERN" ) {print $0}}'  filename

that looks like it could do just what i need, don't care about it being truncated, but I'm getting this error when trying to run it.



awk '{if ( substr($0,1,200) ~ "@my.domain.com rfc822" ) {print $0}}' logfile1
awk: syntax error near line 1
awk: illegal statement near line 1
awk: syntax error near line 1
awk: bailing out near line 1

You could use the cut command first:

#!/bin/bash
# Must have at least two args: pattern file...

if [ $# -lt 2 ] ; then
cat <<END
usage: $0 pattern files
Looks for regex pattern in first 200 chars of each file.
END

else
  pattern=$1
  shift 1

  for f in "$@" ; do
      tempf=`basename $f`.$$
      grep -H -n ".*" $f | cut -d":" -f1,2 > $tempf
      cut -c1-20 $f | paste -d":" $tempf - | grep -e "$pattern"
      rm -f $tempf
  done
fi

Oops, that should be   cut -c1-200  

bt707, if I recall correctly, you're running Solaris;  I've just tested it on Solaris 8 using nawk instead of basic awk, and nawk executes without errors:

nawk '{if ( substr($0,1,200) ~ "@my.domain.com rfc822" ) {print $0}}' logfile1

This simplified version might work with standard Solaris awk - But  I won't be able to test it until tomorrow now...
awk ' substr($0,1,200) ~ "@my.domain.com rfc822"  {print $0}' logfile1

Posted again with minor corrections:

#!/bin/bash
# Must have at least two args: pattern file...
if [ $# -lt 2 ] ; then
cat <<END
usage: $0 pattern files
Looks for regex pattern in first 200 chars of each file.
END

else
  pattern=$1
  shift 1

  for f in "$@" ; do
      tempf=/tmp/`basename $f`.$$
      grep -H -n ".*" $f | cut -d":" -f1,2 > $tempf
      cut -c1-200 $f | paste -d":" $tempf - | grep -h -e "$pattern"
      rm -f $tempf
  done
fi

tfewster, thanks for all of your great answers, i used this last one and works great, just what I needed, haven't had time to try the other ones but sure they are all good ones.


Thanks again to All: