使用“sed命令”在多输出文件中使用“F服务..”启动打印行

Question

I developed a script using sed to retrieve lines starting by text F servedM.. from a given multilines file :

• I have an input.txt file of 100000 line
• I want to generate an output.txt containing all line starting by F servedMyd and all lines starting by F servedPuid .

I am using ksh on Red Hat 7.4.

Below I give the code I tried.

#!/bin/ksh
input.txt=$1
while read line
do
sed "/^F servedMyd/p" $input.txt >> output.txt
sed "/^F servedPuid/p" $input.txt >> output.txt
done < $input.txt
exit 0

With this code, I didn't get any output. I expected having an output file with the following structure:

Answer 1

A script is unnecessary, a single line of sed should be sufficient:

sed -n '/^F served\(My\|Pui\)d/p' foo > bar

Or grep :

grep '^F served\(My\|Pui\)d' foo > bar

Or:

grep -E '^F served(My|Pui)d' foo > bar