explain_strtof(3)

💖 explain_strtof — NAME 💖

okay bestie, so this page is explain_strtof — it explains strtof(3) errors. That's it, that's the whole job. It's the explain_strtof(3) page from the Library Functions Manual, and she's here to make your float-parsing failures make sense. 💅

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🌸 SYNOPSIS 🌸

#include <libexplain/strtof.h>
const char *explain_strtof(const char *nptr, char **endptr);
const char *explain_errno_strtof(int errnum, const char *nptr, char **endptr);
void explain_message_strtof(char *message, int message_size, const char *nptr, char **endptr);
void explain_message_errno_strtof(char *message, int message_size, int errnum, const char *nptr, char **endptr);

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✨ DESCRIPTION ✨

These functions are your little support system when strtof(3) ghosts you with an error. You call one of them, and you get back an explanation — actual words, in a string, telling you what went wrong. Obsessed. 🫶

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🎀 explain_strtof 🎀

const char *explain_strtof(const char *nptr, char **endptr);

The explain_strtof function gets you an explanation of an error returned by the strtof(3) system call. The least the message will contain is the value of strerror(errno), but usually it does way better than the bare minimum and points at the actual underlying cause in more detail. She's an overachiever, no cap. ✨

The errno global variable is what she reads to grab the error value that needs decoding.

• nptr — the original nptr, exactly as passed to the strtof(3) system call.
• endptr — the original endptr, exactly as passed to the strtof(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. It gets overwritten by the next call to any libexplain function which shares this buffer, including calls from other threads. So like… copy it if you care, bestie. 😭

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

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

float result = strtof(nptr, endptr);
if (result < 0)
{
    fprintf(stderr, "%s\n", explain_strtof(nptr, endptr));
    exit(EXIT_FAILURE);
}

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

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🦋 explain_errno_strtof 🦋

const char *explain_errno_strtof(int errnum, const char *nptr, char **endptr);

The explain_errno_strtof function gets you an explanation of an error returned by the strtof(3) system call. The least the message will contain is the value of strerror(errno), but usually it does much better and shows you the underlying cause in more detail. 💜

• errnum — the error value to be decoded, usually grabbed from the errno global variable just before this function is called. You need this if you have to run any code between the system call to be explained and this function, because many libc functions will alter the value of errno. She's not being dramatic, that's just how it is. 💀
• nptr — the original nptr, exactly as passed to the strtof(3) system call.
• endptr — the original endptr, exactly as passed to the strtof(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. It 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:

float result = strtof(nptr, endptr);
if (result < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_strtof(err, nptr, endptr));
    exit(EXIT_FAILURE);
}

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

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🌈 explain_message_strtof 🌈

void explain_message_strtof(char *message, int message_size, const char *nptr, char **endptr);

The explain_message_strtof function gets you an explanation of an error returned by the strtof(3) system call. The least the message will contain is the value of strerror(errno), but usually it does much better and shows the underlying cause in more detail. 🌟

The errno global variable is what she uses 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. Look at her go, main character energy. 👑
• message_size — the size in bytes of the location in which to store the returned message.
• nptr — the original nptr, exactly as passed to the strtof(3) system call.
• endptr — the original endptr, exactly as passed to the strtof(3) system call.

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

float result = strtof(nptr, endptr);
if (result < 0)
{
    char message[3000];
    explain_message_strtof(message, sizeof(message), nptr, endptr);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

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👑 explain_message_errno_strtof 👑

void explain_message_errno_strtof(char *message, int message_size, int errnum, const char *nptr, char **endptr);

The explain_message_errno_strtof function gets you an explanation of an error returned by the strtof(3) system call. The least the message will contain is the value of strerror(errno), but usually it does much better and indicates the underlying cause in more detail. Fr fr. 💖

• 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.
• nptr — the original nptr, exactly as passed to the strtof(3) system call.
• endptr — the original endptr, exactly as passed to the strtof(3) system call.

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

float result = strtof(nptr, endptr);
if (result < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_strtof(message, sizeof(message), err, nptr, endptr);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

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🔥 SEE ALSO 🔥

• strtof(3) — convert ASCII string to floating-point number ✨
• explain_strtof_or_die(3) — convert ASCII string to floating-point number and report errors 💅

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💜 COPYRIGHT 💜

libexplain version 1.4 Copyright (C) 2009 Peter Miller

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and that's the whole page bestie, you ate that 🍓✨ this little legend is explain_strtof(3) from the Library Functions Manual, shipped as part of libexplain version 1.4, © 2009 Peter Miller — mwah, no notes, periodt. 🎀🦋💖