CODEWITHSUNDEEP
regexbashunixparsing
cleg
cleg

Reputation: 5022

Parse string with bash and extract number

I've got supervisor's status output, looking like this. 

frontend                         RUNNING    pid 16652, uptime 2:11:17
nginx                            RUNNING    pid 16651, uptime 2:11:17
redis                            RUNNING    pid 16607, uptime 2:11:32

I need to extract nginx's PID. I've done it via grep -P command, but on remote machine grep is build without perl regular expression support.

Looks like sed or awk is exactly what I need, but I don't familiar with them.

Please help me to find a way how to do it, thanks in advance.

Upvotes: 21

Views: 42102

Answers (6)

Ether
Ether

Reputation: 53966

Take a look at pgrep, a variant of grep specially tailored for grepping process tabless.

Upvotes: 2

intuited
intuited

Reputation: 24034

assuming that the grep implementation supports the -o option, you could use two greps:

output \
  | grep -o '^nginx[[:space:]]\+[[:upper:]]\+[[:space:]]\+pid [0-9]\+' \
  | grep -o '[0-9]\+$'

Upvotes: 1

Dennis Williamson
Dennis Williamson

Reputation: 359885

Using AWK alone:

awk -F'[ ,]+' '{print $4}' inputfile

Upvotes: 8

Vinko Vrsalovic
Vinko Vrsalovic

Reputation: 340171

Solution with awk and cut

vinko@parrot:~$ cat test
frontend                         RUNNING    pid 16652, uptime 2:11:17
nginx                            RUNNING    pid 16651, uptime 2:11:17
redis                            RUNNING    pid 16607, uptime 2:11:32
vinko@parrot:~$ awk '{print $4}' test | cut -d, -f 1
16652
16651
16607

for nginx only:

vinko@parrot:~$ grep nginx test | awk '{print $4}' | cut -d, -f 1
16651

Upvotes: 6

reko_t
reko_t

Reputation: 56430

sed 's/.*pid \([0-9]*\).*/\1/'

Upvotes: 26

Stephen
Stephen

Reputation: 49156

$ cat $your_output | sed -s 's/.*pid \([0-9]\+\),.*/\1/'
16652
16651
16607

Upvotes: 8

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