> What's happening? 1) $ awk '/Date/' respaldo Runs awk with the program-text "/Date/" on the input-file respaldo. This program is only a pattern. The default action is to print the entire line of the input-file to the screen if the pattern matches.
2) $ cat respchk /Date/ respaldo $ awk -f respchk This runs awk with the program-file respchk but without an input-file. The respchk program-file consists of the pattern "/Date/ respaldo". respaldo is interpreted as a variable here and because it's empty (by default), it doesn't have an effect on the program. As there is no input-file specified, awk 'hangs', that is, waits for input from stdin. A program-file for the awk statement in 1) would only consist of "/Date/" and you would specify the input-file on the command line: 3) $ cat respchk /Date/ $ awk -f respchk respaldo With the "#!" line, assuming the path "/usr/bin/awk" is valid ($ which awk) and respchk is executable ($ chmod +x respchk), this would look like 4) $ cat respchk #! /usr/bin/awk -f /Date/ $ ./respchk respaldo respchk is now the program and respaldo is the input-file again. Hope this helps. BTW: Can somebody give me a clue why awk is /usr/bin/awk in Debian (also e.g., ksh) (and /bin/awk in most other systems I've seen)? What's the standard "#! " way to get a script running on both? ln -s /usr/bin/<prg> /bin/<prg> in Debian (and vice versa in other systems)? (please cc me) Andreas
