explain_execv(3)

✨ explain_execv(3) ✨

okay bestie, gather round, because this is one of those pages from the Library Functions Manual and it's literally the glow-up your error messages have been begging for 💅

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🌸 NAME 🌸

explain_execv — the girl who explains your execv(3) errors to you in full sentences instead of just vibes 🫶

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🎀 SYNOPSIS 🎀

#include <libexplain/execv.h>
const char *explain_execv(const char *pathname, char *const*argv);
const char *explain_errno_execv(int errnum, const char *pathname, char
*const*argv);
void explain_message_execv(char *message, int message_size, const char
*pathname, char *const*argv);
void explain_message_errno_execv(char *message, int message_size, int
errnum, const char *pathname, char *const*argv);

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💖 DESCRIPTION 💖

So these functions? They exist so you can get actual explanations for errors coming back from the execv(3) system call. No more staring at a bare errno like 👁️👄👁️. We got you.

🌟 explain_execv

const char *explain_execv(const char *pathname, char *const*argv);

The explain_execv function is used to obtain an explanation of an error returned by the execv(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 for it 👑

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

• pathname — the original pathname, exactly as passed to the execv(3) system call. no edits, no touch-ups, the raw thing 💫
• argv — the original argv, exactly as passed to the execv(3) system call. same energy, untouched.

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. 😭 she's a communal girlie.

Note: This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library. fr fr, don't be messy with it.

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

if (execv(pathname, argv) < 0)
{
    fprintf(stderr, "%s\n", explain_execv(pathname, argv));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_execv_or_die(3) function. cute, convenient, already done for you 💖

🦋 explain_errno_execv

const char *explain_errno_execv(int errnum, const char *pathname, char
*const*argv);

The explain_errno_execv function is used to obtain an explanation of an error returned by the execv(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. same slay, different signature.

• 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. snatch it early or it's gone 🙈
• pathname — the original pathname, exactly as passed to the execv(3) system call.
• argv — the original argv, exactly as passed to the execv(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.

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

if (execv(pathname, argv) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_execv(err, pathname,
    argv));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_execv_or_die(3) function. ✨

🌈 explain_message_execv

void explain_message_execv(char *message, int message_size, const char
*pathname, char *const*argv);

The explain_message_execv function is used to obtain an explanation of an error returned by the execv(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.

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

• message — the location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe. she said "I bring my own buffer" 👑
• message_size — the size in bytes of the location in which to store the returned message.
• pathname — the original pathname, exactly as passed to the execv(3) system call.
• argv — the original argv, exactly as passed to the execv(3) system call.

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

if (execv(pathname, argv) < 0)
{
    char message[3000];
    explain_message_execv(message, sizeof(message), pathname,
    argv);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_execv_or_die(3) function. 💫

💜 explain_message_errno_execv

void explain_message_errno_execv(char *message, int message_size, int
errnum, const char *pathname, char *const*argv);

The explain_message_errno_execv function is used to obtain an explanation of an error returned by the execv(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. the final boss form, honestly 🔥

• 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.
• pathname — the original pathname, exactly as passed to the execv(3) system call.
• argv — the original argv, exactly as passed to the execv(3) system call.

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

if (execv(pathname, argv) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_execv(message, sizeof(message), err,
    pathname, argv);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_execv_or_die(3) function. 🎀

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⭐ SEE ALSO ⭐

• execv(3) — execute a file
• explain_execv_or_die(3) — execute a file and report errors

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👑 COPYRIGHT 👑

libexplain version 1.4 Copyright (C) 2012 Peter Miller

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and that's the whole page bestie, you ate 💅 mwah — stay hydrated, pass errno early, and remember: this was explain_execv(3), brought to you by libexplain version 1.4, © 2012 Peter Miller 🌸🦋