awk - Assigning system command's output to variable

Question

I want to run the system command in an awk script and get its output stored in a variable. I've been trying to do this, but the command's output always goes to the shell and I'm not able to capture it. Any ideas on how this can be done?

Example:

$ date | awk --field-separator=! {$1 = system("strip $1"); /*more processing*/}

Should call the strip system command and instead of sending the output to the shell, should assign the output back to $1 for more processing. Rignt now, it's sending output to shell and assigning the command's retcode to $1.

Answer 1

Note: Coprocess is GNU awk specific. Anyway another alternative is using getline

cmd = "strip "$1
while ( ( cmd | getline result ) > 0 ) {
  print  result
} 
close(cmd)

Calling close(cmd) will prevent awk to throw this error after a number of calls?:

fatal: cannot open pipe `…' (Too many open files)