Shell Programming and Scripting

perl -nle 'if(/REGEX/){print; $m++; close ARGV if $m>=10}' example

To get the best advice on transforming, extracting, manipulating data,
please supply your computing environment and problem context:

1. OS and shell, preferably with versions
2. Representative sample input
3. Output desired that corresponds to the input
4. Logic to obtain output from input
5. Attempts at a solution that you have tried, including output

Post code and data inside CODE tags.

If you need to use or to avoid certain tools, you may need
to explain why, especially if your post count is low. Once the
problem is identified, responders often can choose the most
appropriate tool, not necessarily the one you might want.

These guidelines allow responders to create solutions without
ambiguity and to avoid creating sample data sets.

egrep -i "abc|bcd|cde" file.txt

egrep -i "abc|bcd|cde" file.txt | head -10

awk 'match ($0, PAT) && ++T[substr($0, RSTART, RLENGTH)]<4' PAT="abc|bcd|cde" file2
abc1
bcd1
abc2
abc3
bcd2
bcd3
cde1
cde2
cde3

bash-3.00$ awk 'match ($0, PAT) && ++T[substr($0, RSTART, RLENGTH)]<4' PAT="abc|bcd|cde" file2.txt
awk: syntax error near line 1
awk: bailing out near line 1