explain_waitpid(3)

✨ explain_waitpid — the manual page, but make it cute ✨

okay bestie, so this is explain_waitpid(3) from the Library Functions Manual — literally the libexplain girlies who explain your waitpid(2) errors to you in full sentences instead of just yelling "error" at your face. iconic behaviour fr fr 💅

---

🌸 NAME 🌸

explain_waitpid — bestie, it explains waitpid(2) errors 💖

---

🎀 SYNOPSIS 🎀

#include <libexplain/waitpid.h>
const char *explain_waitpid(int pid, int *status, int options);
const char *explain_errno_waitpid(int errnum, int pid, int *status, int
options);
void explain_message_waitpid(char *message, int message_size, int pid,
int *status, int options);
void explain_message_errno_waitpid(char *message, int message_size, int
errnum, int pid, int *status, int options);

---

🦋 DESCRIPTION 🦋

These functions are your little translators, okay? You use them to get explanations for errors that the waitpid(2) system call threw at you. It's giving "here's what actually went wrong, babe" ✨

💜 explain_waitpid

const char *explain_waitpid(int pid, int *status, int options);

The explain_waitpid function gets you an explanation of an error returned by the waitpid(2) system call. The least the message will contain is the value of strerror(errno), but usually it's gonna do so much better and tell you the underlying cause in more detail. no cap.

The errno global variable will be used to obtain the error value to be decoded. she reads your mind (well, your errno) 💅

This function is intended to be used in a fashion similar to the following example:

if (waitpid(pid, status, options) < 0)
{
    fprintf(stderr, "%s\n", explain_waitpid(pid, status, options));
    exit(EXIT_FAILURE);
}

• pid — the original pid, exactly as passed to the waitpid(2) system call. like, don't get creative with it, bestie 🫶
• status — the original status, exactly as passed to the waitpid(2) system call.
• options — the original options, exactly as passed to the waitpid(2) system call.

Returns:

The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads. so like, she's not yours, she's everybody's 😭

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library. periodt.

---

💖 explain_errno_waitpid

const char *explain_errno_waitpid(int errnum, int pid, int *status, int
options);

The explain_errno_waitpid function gets you an explanation of an error returned by the waitpid(2) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better and indicate the underlying cause in more detail. obsessed with the detail ngl ✨

This function is intended to be used in a fashion similar to the following example:

if (waitpid(pid, status, options) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_waitpid(err,
        pid, status, options));
    exit(EXIT_FAILURE);
}

• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno. like, they will simply snatch it, bestie 🙈
• pid — the original pid, exactly as passed to the waitpid(2) system call.
• status — the original status, exactly as passed to the waitpid(2) system call.
• options — the original options, exactly as passed to the waitpid(2) system call.

Returns:

The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

---

🍓 explain_message_waitpid

void explain_message_waitpid(char *message, int message_size, int pid,
int *status, int options);

The explain_message_waitpid function may be used to obtain an explanation of an error returned by the waitpid(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better and indicate the underlying cause in more detail. she's thorough, she's thoughtful, she's the moment 💅

The errno global variable will be used to obtain the error value to be decoded.

This function is intended to be used in a fashion similar to the following example:

if (waitpid(pid, status, options) < 0)
{
    char message[3000];
    explain_message_waitpid(message, sizeof(message), pid, status, options);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

• message — the location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe. slay, you brought your own buffer 💖
• message_size — the size in bytes of the location in which to store the returned message.
• pid — the original pid, exactly as passed to the waitpid(2) system call.
• status — the original status, exactly as passed to the waitpid(2) system call.
• options — the original options, exactly as passed to the waitpid(2) system call.

---

🌈 explain_message_errno_waitpid

void explain_message_errno_waitpid(char *message, int message_size, int
errnum, int pid, int *status, int options);

The explain_message_errno_waitpid function may be used to obtain an explanation of an error returned by the waitpid(2) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better and indicate the underlying cause in more detail. she ate and left no crumbs fr fr 👑

This function is intended to be used in a fashion similar to the following example:

if (waitpid(pid, status, options) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_waitpid(message, sizeof(message), err,
        pid, status, options);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

• message — the location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
• message_size — the size in bytes of the location in which to store the returned message.
• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.
• pid — the original pid, exactly as passed to the waitpid(2) system call.
• status — the original status, exactly as passed to the waitpid(2) system call.
• options — the original options, exactly as passed to the waitpid(2) system call.

---

👀 SEE ALSO 👀

• waitpid(2) — wait for process to change state 🧚
• explain_waitpid_or_die(3) — wait for process to change state and report errors 💀

---

💜 COPYRIGHT 💜

libexplain version 1.4 Copyright (C) 2008 Peter Miller

---

and that's the whole page bestie!! thanks for reading my little explain_waitpid(3) breakdown from the Library Functions Manual — libexplain version 1.4, copyright (C) 2008 Peter Miller, mwah 💖✨🎀🦋