explain_execlp(3)

💖 explain_execlp(3) 💖

okay bestie, gather round, because this is one of those libexplain pages and it's genuinely so useful once it clicks. it's part of the Library Functions Manual, and no cap, it's giving "your error messages deserve to be iconic" energy.

---

✨ NAME ✨

explain_execlp — explain execlp(3) errors

like, literally. that's the whole job. it takes the mysterious little error your execlp(3) call threw at you and turns it into words a human can read. 🫶

---

🌸 SYNOPSIS 🌸

#include <libexplain/execlp.h>
const char *explain_execlp(, ...);
const char *explain_errno_execlp(int errnum, , ...);
void explain_message_execlp(char *message, int message_size, , ...);
void explain_message_errno_execlp(char *message, int message_size, int
errnum, , ...);

yes, those signatures really do have , ... in them, that's not a typo on my part, that's just the vibe. 💅

---

🦋 DESCRIPTION 🦋

these functions are your little translators. you use them to get explanations for errors returned by the execlp(3) system call. so instead of staring at a cryptic number like 👁️👄👁️ you get an actual sentence about what went wrong.

---

🎀 explain_execlp

const char *explain_execlp(, ...);

the explain_execlp function is used to obtain an explanation of an error returned by the execlp(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. so it's the bare minimum at worst, and actually helpful at best. periodt.

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

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, don't hold onto it, bestie, it's not yours to keep. 😭

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 (execlp() < 0)
{
    fprintf(stderr, "%s\n", explain_execlp());
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_execlp_or_die(3) function. so if you're feeling lazy (valid), someone already did the work for you. 👑

---

💜 explain_errno_execlp

const char *explain_errno_execlp(int errnum, , ...);

the explain_errno_execlp function is used to obtain an explanation of an error returned by the execlp(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.

• 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. so like, grab that number immediately, don't go running errands first. 🏃♀️

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 (execlp() < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_execlp(err, ));
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_execlp_or_die(3) function.

---

🌈 explain_message_execlp

void explain_message_execlp(char *message, int message_size, , ...);

the explain_message_execlp function is used to obtain an explanation of an error returned by the execlp(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. ooh, look at you, bringing your own buffer. main character energy. ✨
• message_size — the size in bytes of the location in which to store the returned message.

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

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

the above code example is available pre‐packaged as the explain_execlp_or_die(3) function.

---

🧚 explain_message_errno_execlp

void explain_message_errno_execlp(char *message, int message_size, int
errnum, , ...);

the explain_message_errno_execlp function is used to obtain an explanation of an error returned by the execlp(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.

• 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.

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

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

the above code example is available pre‐packaged as the explain_execlp_or_die(3) function.

---

🍓 SEE ALSO 🍓

• execlp(3) — execute a file
• explain_execlp_or_die(3) — execute a file and report errors

---

👑 COPYRIGHT 👑

• libexplain version 1.4
• Copyright (C) 2009 Peter Miller

---

and that's the whole page, bestie!! 💖 this little legend came to you from libexplain version 1.4, with the copyright living in 2009 and belonging to Peter Miller, and the page itself signs off as explain_execlp(3). go forth and have beautifully explained errors. slay. 🦋✨