awk pipes & print

Shell Programming and Scripting
1

Hi,

I need to awk some data from some text files, basic stuff, eg:

awk '/phrase/ {print $1,$2,$3}' file

Which will print columns 1 to 3 of all lines containing "phrase"

But what if I wanted to pipe just one of the columns to a command (in my case a date converter) as in:

awk '/phrase/ {print $1 � "command" ,$2,$3}' file

The above does not work. Does anyone know what does? I'm using ksh.

Cheers, Jon.

2

Your date converter has to be able to read from stdin. Your syntax is mostly correct. use getline to "retreive" your response on the other side of the pipe.

awk '/phrase/ {print $1 � "command" | getline mydate; print mydate,$2,$3}' file

Test your date converter on the command line:

echo "$mydate" | date_converter
3

try this

awk '/phrase/ {print $1,$2,$3 ; system("command "$1)}' file
4

Here is another example using gawk

/phase/ {
      tmp = "date -r "$1;
      tmp | getline epoch;
      close(date);
      print epoch, $2, $3;
}

Sample file

2000  2 3 phase
90000 5 6 phase
7000  8 9

Output

Wed Dec 31 19:33:20 EST 1969 2 3
Thu Jan  1 20:00:00 EST 1970 5 6
5

Thanks guys and thanks for this ynixon, which is quite elegant and what I was looking for. I'm using:

awk '/phrase/ {system("command "$1" ");print $3" "$4}' file > output

...the only problem is the ; forces a new line. Any way around that?

Jon