![Pattern to Get String Between Two Specific Words/Characters Using Grep [Duplicate]](https://docuprint.cloud68.co/uploads/pattern-to-get-string-between-two-specific_1200.jpg)
I need to extract email address from a string like this (I'm making a log parser):
<some text> from=, <some text>
with egrep (or grep -Eo). So the string needs to be pulled out only between "from=" and "," , because the other parts of log contain email addresses too, like to= and etc
3 Answers
Using grep -oP:
s='<some text> from=, <some text>'
grep -oP '(?<=from=).*?(?=,)' <<< "$s"
OR else avoid lookbehind by using \K:
grep -oP 'from=\K.*?(?=,)' <<< "$s"
In case your grep doesn't support -P (PCRE) use this sed:
sed 's/.*from=\(.*\),.*/\1/' <<< "$s"
Try awk
echo '<text> from=, <text>' | awk -F[=,] '{print $2}'
Here $2 can be a different number based on its position.
Sample for word between symbols "(", ")":
echo "Linux Foundation Certified Engineer (LFCE-JP)" | awk -F[\(\)] '{print $2}'
LFCE-JP
A purely bash solution, requires two steps to strip prefix & suffix separately (but probably runs faster, because no subprocesses):
#!/bin/bash
orig='from=, <some text>'
one=${orig#*from=}
two=${one%,*}
printf "Result:\n"
printf "$orig\n"
printf "$one\n"
printf "$two\n"
Output:
Result:
from=, <some text>
, <some text>
Notes:
${var#*pattern}using#strips from the start of$varup topattern${var%pattern*}using%strips from end of$var, up topattern- similar could be accomplished with
${var/pattern/replace}(and leavingreplaceblank), but it's trickier since full regexp isn't supported (ie, can't use^or '$'), so you can't do (for example)/^from=//, but you could do in step one${var/*from=/}and then in step two, do${var/,*/}(depending on your data, of course). - see also:
