I’m trying to get first field value using awk field separator, but it is failing as below. Same is working fine when i’m trying with echo manually.
Fail Case 1:
[root@centos ~]# ssh -V | awk -F_ '{print $1}'
Output: OpenSSH_8.7p1, OpenSSL 3.0.7 1 Nov 2022
Fail Case 2:
[root@centos ~]# ssh -V | awk 'BEGIN{FS="_"} {print $1}'
Output: OpenSSH_8.7p1, OpenSSL 3.0.7 1 Nov 2022
Working Case with "echo"
[root@centos ~]# echo "OpenSSH_8.7p1, OpenSSL 3.0.7 1 Nov 2022" | awk -F_ '{print $1}'
Output: OpenSSH
I found a similar problem here but it’s not working in my case. What is it i’m failing to understand here?
>Solution :
ssh -V is writing its output to stderr, not stdout, so what you are seeing printed is the error stream that didn’t go through awk at all.
An easy fix: redirect stderr to stdout.
ssh -V 2>&1 | awk -F_ '{print $1}'