NAME

fork, wait, waitpid - basic process management

SYNOPSIS

@load "fork"

pid = fork()

ret = waitpid(pid)

ret = wait();

DESCRIPTION

The fork extension adds three functions, as follows.

fork()

    This function creates a new process. The return value is the zero in
    the child and the process-id number of the child in the parent, or
    -1 upon error. In the latter case, ERRNO indicates the problem. In
    the child, PROCINFO["pid"] and PROCINFO["ppid"] are updated to
    reflect the correct values.

waitpid()

    This function takes a numeric argument, which is the process-id to
    wait for. The return value is that of the waitpid(2) system call.

wait()

    This function waits for the first child to die. The return value is
    that of the wait(2) system call.

BUGS

There is no corresponding exec() function.

The interfaces could be enhanced to provide more facilities, including
pulling out the various bits of the return status.

EXAMPLE

    @load "fork"
    ...
    if ((pid = fork()) == 0)
        print "hello from the child"
    else
        print "hello from the parent"

SEE ALSO

GAWK: Effective AWK Programming, and the man pages for the other
extensions shipped with gawk.

fork(2), wait(2), waitpid(2).

AUTHOR

Arnold Robbins, arnold@skeeve.com.

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