A common way awk scripts are written is to use top-level pattern-action blocks. The file would then consist of multiple top-level pattern-action blocks. Each block would apply to input lines matching its pattern. This works well for simple operations intended for a single purpose.

I would like my awk files to have the capability of performing more than a single specific operation on the data.

Have found that to perform different operations conditionally or modularly, top-level blocks alone become unwieldy.

Using functions with a mode variable for each operation I want to perform can be used to select which function to call for each input line. Which lets me write a single main block that dispatches processing based on the mode.

function operation1(line) {
  # code for operation 1
}

function operation2(line) {
  # code for operation 2
}

{
  if (mode == "op1") {
    operation1($0)
  } else if (mode == "op2") {
    operation2($0)
  } else {
    # default action
    print $0
  }
}

I then pass the mode variable from the command line:

awk -v mode=op1 -f script.awk inputfile

Is this the way to accomplish what I want. Are there other ways that can be utilised.

A common way awk scripts are written is to use top-level pattern-action blocks. The file would then consist of multiple top-level pattern-action blocks. Each block would apply to input lines matching its pattern. This works well for simple operations intended for a single purpose.

I would like my awk files to have the capability of performing more than a single specific operation on the data.

Have found that to perform different operations conditionally or modularly, top-level blocks alone become unwieldy.

Using functions with a mode variable for each operation I want to perform can be used to select which function to call for each input line. Which lets me write a single main block that dispatches processing based on the mode.

function operation1(line) {
  # code for operation 1
}

function operation2(line) {
  # code for operation 2
}

{
  if (mode == "op1") {
    operation1($0)
  } else if (mode == "op2") {
    operation2($0)
  } else {
    # default action
    print $0
  }
}

I then pass the mode variable from the command line:

awk -v mode=op1 -f script.awk inputfile

Is this the way to accomplish what I want? Are there other ways that can be used?