CODEWITHSUNDEEP
linuxbashshell
sai kumar
sai kumar

Reputation: 15

Unable to use grep for a command and excecute the shell script?

I have created a shell script to execute 5 commands from a file called elist.txt

ps -ef | grep user | grep 'process -s 9000' | cut -c -15 | cut -c 10-
ps -ef | grep user | grep 'process -s 9001' | cut -c -15 | cut -c 10-
ps -ef | grep user | grep 'process -s 9002' | cut -c -15 | cut -c 10-
ps -ef | grep user | grep 'process -s 9003' | cut -c -15 | cut -c 10-

The shell script is as follows

export PATH="/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/user/.local/bin:/home/user/bin"
input="/home/user/script/list.txt"
while IFS= read -r line
do
echo $($line)
done < "$input"

output:

error: garbage option

Usage:
 ps [options]

 Try 'ps --help <simple|list|output|threads|misc|all>'
  or 'ps --help <s|l|o|t|m|a>'
 for additional help text.

For more details see ps(1).

Upvotes: 0

Views: 529

Answers (2)

Matias Barrios
Matias Barrios

Reputation: 5056

You can do this too. People usually do not recommend to use eval at all.

export PATH="/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/user/.local/bin:/home/user/bin"
input="/home/user/script/list.txt"
while IFS= read -r line
do
bash -c "$line"
done < "$input"

Regards!

Upvotes: 1

Aleksandar
Aleksandar

Reputation: 2642

I would use this script with eval which is a similar solution described in this answer https://stackoverflow.com/a/6002329/6778826

export PATH="/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/user/.local/bin:/home/user/bin"
input="/home/user/script/list.txt"
while read -r line
do
  eval "$line"
done <$input

Upvotes: 1

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