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@mohitesachin217
Created June 19, 2016 13:27
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search textfiles with regular expressions
--grep,
--fgrep,
--egrep
--regex
grep search through stream
syntax
grep [string to find] [file name]
grep -n[string to find] ] [filename]
grep is case sensitive to make case insensitive add -i flag
regular expressions inside the grep
^ == means == starts with grep ^boo file.txt == list all the lines with boo starting
$ == means == ends with grep oks$ file.txt == list all the lines with oks ending
. == means == any single character grep .oo file.txt == list all the lines with any character start but oo next characters
egrep: grep with more regular expression
egrep '^(b|d)' file.txt search all the words that starts with either b or d
egrep '(b|d)oo' file.txt search all the words that starts with b or d and followed by oo
fgrep dosent support any kind of regular expresstion
man regex command for more information
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