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#include <sys/wait.h>
#include <stdint.h>
#include <unistd.h>
#include "warnp.h"
#include "fork_func.h"
/**
* fork_func(func, cookie):
* Fork and run ${func} in a new process, with ${cookie} as the sole argument.
*/
pid_t
fork_func(int (* func)(void *), void * cookie)
{
pid_t pid;
/* Fork */
switch (pid = fork()) {
case -1:
/* Error in fork system call. */
warnp("fork");
goto err0;
case 0:
/* In child process: Run the provided function, then exit. */
_exit(func(cookie));
default:
/* In parent process: do nothing else. */
break;
}
/* Success! */
return (pid);
err0:
/* Failure! */
return (-1);
}
/**
* fork_func_wait(pid):
* Wait for the process ${pid} to finish. Print any error arising from ${pid}.
* If ${pid} exited cleanly, return its exit code; otherwise, return -1.
*/
int
fork_func_wait(pid_t pid)
{
int status;
int rc = -1;
/* Wait for the process to finish. */
if (waitpid(pid, &status, 0) == -1) {
warnp("waitpid");
goto err0;
}
/* Print the error status, if applicable. */
if (WIFEXITED(status)) {
/* Child ${pid} exited cleanly. */
rc = WEXITSTATUS(status);
} else {
/*
* Child ${pid} did not exit cleanly; warn about the reason
* for the unclean exit.
*/
if (WIFSIGNALED(status))
warn0("pid %jd: terminated with signal %d",
(intmax_t)pid, WTERMSIG(status));
else
warn0("pid %jd: exited for an unknown reason",
(intmax_t)pid);
}
err0:
/* Done! */
return (rc);
}
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