How to call an external program using AWK?

How to call an external program using AWK?

awk‘s system (cmd) function can call an external command and get the exit status. This function is the key to solving the problem. First, let’s have a look at how the problem gets solved:

How does the AWK function in Perl work?

Awk works with condition {action} pairs. If the action is omitted, the default is to print the current line if the condition returns true. Awk, like many C-like languages, treats 1 as true. (For completeness, if the condition is omitted, the action will be executed for each record.) Many perl functions take advantage of the “default” variable.

How to get current date and time in AWK?

The magic happens in close (cmd) statement. It forces awk to execute cmd each time, so, date would be actual one each time. cmd | get line d reads output from cmd and saves it to d.

How many times can you repeat a line in Perl?

You can do this without requiring sed, perl, or awk. Will repeat each line 4 times. Where you repeat each line 3 more times. @potong ‘s answer does not work with empty lines, replacing \\+ with * should fix it:

How to run CMD in AWK Stack Overflow?

In form cmd | getline result, cmd is run, then its output is piped to getline. It returns 1 if got output, 0 if EOF, -1 on failure. First construct the command to run in a variable in the BEGIN clause if the command is not dependant on the contents of the file, e.g. a simple date or an ls.

When to use AWK and system function in Bash?

I want to use awk and the system () function to move a couple of directories around. I have a file that I want to process with awk names file.cfg which is organized in the following way:

Which is better printf or echo in AWK?

Update In the original answer, I used echo instead of printf. However, printf is the better and more portable alternative as was pointed out by a comment (where great links with discussions can be found). awk has a function called system it enables you to execute any linux bash command within the output of awk.

What does system ( ) return in awk command?

system () in awk returns the exit status of the command rather than its actual output. The command runs, writes its output to standard output, and its exit status (“0”) is what gets returned and assigned to the variable.

How to export a shell function to AWK?

With bash, another option is to export shell functions with export -f, which then become available to awk via the system () call:

Is it possible to execute AWK files using AWK file?

Using an awk file I need to execute all awk files in a current folder. Is it possible to do such operations in awk? Yes you can. You’ll need to use the system () function. I’m assuming you only want to run these scripts once. If so, you can add them to the BEGIN block of your wrapper script: