explain_system(3)

✨ NAME ✨

okay so bestie, this is explain_system from the Library Functions Manual — it's the whole "explain system(3) errors" situation 💅

🌸 SYNOPSIS 🌸

#include <libexplain/system.h>
const char *explain_system(const char *command);
const char *explain_errno_system(int errnum, const char *command);
void explain_message_system(char *message, int message_size, const char
*command);
void explain_message_errno_system(char *message, int message_size, int
errnum, const char *command);

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🦋 DESCRIPTION 🦋

So like, these functions are your little besties for getting explanations of errors that the system(3) system call throws back at you. No cap.

💖 explain_system

const char *explain_system(const char *command);

The explain_system function is the girl you call when you want an explanation of an error returned by the system(3) 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. It's giving overachiever, and we love that ✨

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 (system(command) < 0)
{
    fprintf(stderr, "%s\n", explain_system(command));
    exit(EXIT_FAILURE);
}

• command — The original command, exactly as passed to the system(3) 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. 😭 So like, be careful out there.

🌈 explain_errno_system

const char *explain_errno_system(int errnum, const char *command);

The explain_errno_system function is used to obtain an explanation of an error returned by the system(3) 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 fr fr 💅

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

if (system(command) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_system(err, command));
    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. lowkey sneaky of them ngl.
• command — The original command, exactly as passed to the system(3) 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_system

void explain_message_system(char *message, int message_size, const char
*command);

The explain_message_system function may be used to obtain an explanation of an error returned by the system(3) 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. iconic behaviour honestly.

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 (system(command) < 0)
{
    char message[3000];
    explain_message_system(message, sizeof(message), command);
    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. 👑 you did that.
• message_size — The size in bytes of the location in which to store the returned message.
• command — The original command, exactly as passed to the system(3) system call.

🧚 explain_message_errno_system

void explain_message_errno_system(char *message, int message_size, int
errnum, const char *command);

The explain_message_errno_system function may be used to obtain an explanation of an error returned by the system(3) 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. main character energy tbh 🫶

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

if (system(command) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_system(message, sizeof(message), err, command);
    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. (yes, again. they're messy like that 🙈)
• command — The original command, exactly as passed to the system(3) system call.

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👀 SEE ALSO 👀

• system(3) — execute a shell command
• explain_system_or_die(3) — execute a shell command and report errors

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📜 COPYRIGHT 📜

libexplain version 1.4

Copyright (C) 2008 Peter Miller

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and that's the whole page bestie, we're done 💜

this has been explain_system(3) from the Library Functions Manual, brought to you by libexplain version 1.4, Copyright (C) 2008 Peter Miller — slay, go write some safe code, ily, bye 🎀✨🦋