COMERRNO(3)

💅 COMERRNO(3) 💅

ok so we're in Schily's LIBRARY FUNCTIONS today bestie, and this one is from COMERRNO(3) — yes the number 3, meaning it's a library function, we love a section 3 moment 🎀

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✨ NAME ✨

comerrno() — prints an error message, given an error code, and exits. that's it, that's the whole vibe. it prints and then it dips 💨

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🌸 SYNOPSIS 🌸

comerrno(error,format,args);
int error;
char *format;

like, look at her. error is an int, format is a char *, and args is whatever you're passing through for the format string. clean, simple, iconic.

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🦋 DESCRIPTION 🦋

okay so comerrno() is like comerr(), except — and this is the main character detail — the caller supplies the error number. you're the one bringing the number to the party, not the system. 💅

here's how the number gets read:

• Positive numbers are turned into system error messages. slay, the system knows what you mean.
• Negative numbers cause the system error portion of the output to be omitted. so you just get your own message, no system commentary, no extra noise. lowkey respectful of your privacy honestly 🙈

and the whole point: comerrno() is a convenient way to print the name of the program, and an error message, and exit the process in a single call. three things, one function, no cap. that's efficiency. that's main character energy. 👑

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💀 RETURNS 💀

none. not "none like a sad zero", none like it does not return. bestie it does not come back. 😭

Rather than return, comerrno() exits the current process with a value equal to the error number supplied by the user.

so like… whatever number you handed it, that's your exit status now. hope you meant that. 🫶

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⭐ EXAMPLES ⭐

a whole little moment, here:

if (argc < 2)
     comerrno(-1, "Usage: name arg.\n");

see what she did? negative number → no system error portion, just the usage message, then exit with -1. chef's kiss. 🔥

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🌈 SEE ALSO 🌈

the friend group, in order, exactly as listed:

• comerr(3)
• error(3)
• errmsg(3)
• error(3) — yes it's listed again, she's just that popular 💖
• geterrno(3)
• printf(3)
• format(3)

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🍓 NOTES 🍓

so here's the tea: comerrno() attempts to find a line in the message file that corresponds to the system error number. 🔍

If none can be found, or if it has trouble finding or reading the file, it simply says: error #.

no dramatic failure, no extra chaos — just error # and we move on. graceful under pressure, honestly. 💅✨

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and that's the page!! written by Joerg Schilling, dated 2022/09/09 — shoutout to the author and the version stamp, mwah 😘🦋 hope this helped bestie, go print some errors and exit with confidence 💜