gawk: Do Statement
1
1 7.4.3 The 'do'-'while' Statement
1 --------------------------------
1
1 The 'do' loop is a variation of the 'while' looping statement. The 'do'
1 loop executes the BODY once and then repeats the BODY as long as the
1 CONDITION is true. It looks like this:
1
1 do
1 BODY
1 while (CONDITION)
1
1 Even if the CONDITION is false at the start, the BODY executes at
1 least once (and only once, unless executing BODY makes CONDITION true).
1 Contrast this with the corresponding 'while' statement:
1
1 while (CONDITION)
1 BODY
1
1 This statement does not execute the BODY even once if the CONDITION is
1 false to begin with. The following is an example of a 'do' statement:
1
1 {
1 i = 1
1 do {
1 print $0
1 i++
1 } while (i <= 10)
1 }
1
1 This program prints each input record 10 times. However, it isn't a
1 very realistic example, because in this case an ordinary 'while' would
1 do just as well. This situation reflects actual experience; only
1 occasionally is there a real use for a 'do' statement.
1