fork, wait, waitpid − basic process management
@load "fork"
pid = fork()
ret = waitpid(pid)
ret = wait();
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. |
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.
@load
"fork"
...
if ((pid = fork()) == 0)
print "hello from the child"
else
print "hello from the parent"
GAWK: Effective AWK Programming, filefuncs(3am), fnmatch(3am), inplace(3am), ordchr(3am), readdir(3am), readfile(3am), revoutput(3am), rwarray(3am), time(3am).
fork(2), wait(2), waitpid(2).
Arnold Robbins, [email protected].
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