CODEWITHSUNDEEP
linuxawk
maihabunash
maihabunash

Reputation: 1702

awk + set external var in awk

the following awk syntax cut the lines from the file

from the line that have port XNT1

until END OF COMMAND line

 #  awk '/\/stats\/port XNT1\/if/,/END OF COMMAND/' /var/tmp/test 

  >> SW_02_03 - Main# /stats/port XNT1/if
  ------------------------------------------------------------------
  Interface statistics for port XNT1:
  IBP/CBP Discards:                  0
  L3 Discards:                       0


  >> SW_02_03 - Port Statistics# END OF COMMAND
  # 
  # 
  #

now I set external variable as XNTF=XNT1 in awk command

but from some reason XNTF in the awk not get the "XNT1" value , and awk not display the lines!!!!!!!!

  #  awk -v XNTF=XNT1 '/\/stats\/port XNTF\/if/,/END OF COMMAND/' /var/tmp/test

please advice why awk not works when I set external variable ? and how to fix it ?

Upvotes: 0

Views: 122

Answers (2)

Jotne
Jotne

Reputation: 41460

I normally try to avoid the range command in awk ,, since it not so flexible. This should do:

awk -v XNTF=XNT1 '$0~"/stats/port " XNTF "/if" {f=1} f; /END OF COMMAND/ {f=0}' file
 >> SW_02_03 - Main# /stats/port XNT1/if
  ------------------------------------------------------------------
  Interface statistics for port XNT1:
  IBP/CBP Discards:                  0
  L3 Discards:                       0


  >> SW_02_03 - Port Statistics# END OF COMMAND

Upvotes: 2

Wintermute
Wintermute

Reputation: 44063

Inside //, variables are not expanded. You'll have to use the ~ operator to match against an assembled regex:

awk -v XNTF=XNT1 '$0 ~ "/stats/port " XNTF "/if",/END OF COMMAND/' /var/tmp/test

Generally, $0 ~ some_string matches $0 (the line) against some_string interpreted as a regex.

Upvotes: 1

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