The grep command searches through the file, looking for matches to the pattern specified. To use it type grep , then the pattern we're searching for and finally the name of the file (or files) we're searching in. The output is the three lines in the file that contain the letters 'not'.
To also show you the lines before your matches, you can add -B to your grep. The -B 4 tells grep to also show the 4 lines before the match. Alternatively, to show the log lines that match after the keyword, use the -A parameter. In this example, it will tell grep to also show the 2 lines after the match.
To do this, press Esc , type the line number, and then press Shift-g . If you press Esc and then Shift-g without specifying a line number, it will take you to the last line in the file. To look for the next occurrence after the first, either press n or press / again and then press Enter .
Try using sed as mentioned on http://linuxcommando.blogspot.com/2008/03/using-sed-to-extract-lines-in-text-file.html. For example use
sed '2,4!d' somefile.txt
to print from the second line to the fourth line of somefile.txt. (And don't forget to check http://www.grymoire.com/Unix/Sed.html, sed is a wonderful tool.)
The following command will do what you asked for "extract the lines between 1234 and 5555" in someFile.
sed -n '1234,5555p' someFile
If I understand correctly, you want to find a pattern between two line numbers. The awk one-liner could be
awk '/whatev/ && NR >= 1234 && NR <= 5555' file
You don't need to run grep
followed by sed
.
Perl one-liner:
perl -ne 'if (/whatev/ && $. >= 1234 && $. <= 5555) {print}' file
Line numbers are OK if you can guarantee the position of what you want. Over the years, my favorite flavor of this has been something like this:
sed "/First Line of Text/,/Last Line of Text/d" filename
which deletes all lines from the first matched line to the last match, including those lines.
Use sed -n with "p" instead of "d" to print those lines instead. Way more useful for me, as I usually don't know where those lines are.
Put this in a file and make it executable:
#!/bin/bash
start=`grep -n $1 < $3 | head -n1 | cut -d: -f1; exit ${PIPESTATUS[0]}`
if [ ${PIPESTATUS[0]} -ne 0 ]; then
echo "couldn't find start pattern!" 1>&2
exit 1
fi
stop=`tail -n +$start < $3 | grep -n $2 | head -n1 | cut -d: -f1; exit ${PIPESTATUS[1]}`
if [ ${PIPESTATUS[0]} -ne 0 ]; then
echo "couldn't find end pattern!" 1>&2
exit 1
fi
stop=$(( $stop + $start - 1))
sed "$start,$stop!d" < $3
Execute the file with arguments (NOTE that the script does not handle spaces in arguments!):
To use with your example, use arguments: 1234 5555 myfile.txt
Includes lines with starting and stopping pattern.
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