(gawk.info)Next Statement

The `next' Statement
====================

   The `next' statement forces `awk' to immediately stop processing the
current record and go on to the next record.  This means that no
further rules are executed for the current record.  The rest of the
current rule's action is not executed either.

   Contrast this with the effect of the `getline' function (Note:
Explicit Input with `getline'.).  That too causes `awk' to
read the next record immediately, but it does not alter the flow of
control in any way.  So the rest of the current action executes with a
new input record.

   At the highest level, `awk' program execution is a loop that reads
an input record and then tests each rule's pattern against it.  If you
think of this loop as a `for' statement whose body contains the rules,
then the `next' statement is analogous to a `continue' statement: it
skips to the end of the body of this implicit loop, and executes the
increment (which reads another record).

   For example, if your `awk' program works only on records with four
fields, and you don't want it to fail when given bad input, you might
use this rule near the beginning of the program:

     NF != 4 {
       err = sprintf("%s:%d: skipped: NF != 4\n", FILENAME, FNR)
       print err > "/dev/stderr"
       next
     }

so that the following rules will not see the bad record.  The error
message is redirected to the standard error output stream, as error
messages should be.  Note: Special File Names in `gawk'.

   According to the POSIX standard, the behavior is undefined if the
`next' statement is used in a `BEGIN' or `END' rule.  `gawk' will treat
it as a syntax error.  Although POSIX permits it, some other `awk'
implementations don't allow the `next' statement inside function bodies
(Note: User-defined Functions.).  Just as any other
`next' statement, a `next' inside a function body reads the next record
and starts processing it with the first rule in the program.

   If the `next' statement causes the end of the input to be reached,
then the code in any `END' rules will be executed.  Note: The `BEGIN'
and `END' Special Patterns.

   *Caution:* Some `awk' implementations generate a run-time error if
you use the `next' statement inside a user-defined function (Note:
User-defined Functions.).  `gawk' does not have this
problem.