explain_tempnam(3)

NAME
explain_tempnam - explain tempnam(3) errors

SYNOPSIS
#include <libexplain/tempnam.h>

const char *explain_tempnam(const char *dir, const char *prefix);
const char *explain_errno_tempnam(int errnum, const char *dir, const char *prefix);
void explain_message_tempnam(char *message, int message_size, const char *dir, const char *prefix);
void explain_message_errno_tempnam(char *message, int message_size, int errnum, const char *dir, const char *prefix);

DESCRIPTION
These functions may be used to obtain explanations for errors returned by the tempnam(3) system call.

  explain_tempnam
const char *explain_tempnam(const char *dir, const char *prefix);

The explain_tempnam function is used to obtain an explanation of an error returned by the tempnam(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.

dir The original dir, exactly as passed to the tempnam(3) system call.

prefix
    The original prefix, exactly as passed to the tempnam(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:
    char *result = tempnam(dir, prefix);
    if (!result)
    {
    fprintf(stderr, "%s\n", explain_tempnam(dir, prefix));
        exit(EXIT_FAILURE);
    }

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

  explain_errno_tempnam
const char *explain_errno_tempnam(int errnum, const char *dir, const char *prefix);

The explain_errno_tempnam function is used to obtain an explanation of an error returned by the tempnam(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.

dir The original dir, exactly as passed to the tempnam(3) system call.

prefix
    The original prefix, exactly as passed to the tempnam(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:
    char *result = tempnam(dir, prefix);
    if (!result)
    {
        int err = errno;
    fprintf(stderr, "%s\n", explain_errno_tempnam(err, dir, prefix));
        exit(EXIT_FAILURE);
    }

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

  explain_message_tempnam
void explain_message_tempnam(char *message, int message_size, const char *dir, const char *prefix);

The explain_message_tempnam function is used to obtain an explanation of an error returned by the tempnam(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.

message_size
    The size in bytes of the location in which to store the returned message.

dir The original dir, exactly as passed to the tempnam(3) system call.

prefix
    The original prefix, exactly as passed to the tempnam(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    char *result = tempnam(dir, prefix);
    if (!result)
    {
        char message[3000];
    explain_message_tempnam(message, sizeof(message), dir, prefix);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

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

  explain_message_errno_tempnam
void explain_message_errno_tempnam(char *message, int message_size, int errnum, const char *dir, const char *prefix);

The explain_message_errno_tempnam function is used to obtain an explanation of an error returned by the tempnam(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.

dir The original dir, exactly as passed to the tempnam(3) system call.

prefix
    The original prefix, exactly as passed to the tempnam(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    char *result = tempnam(dir, prefix);
    if (!result)
    {
        int err = errno;
        char message[3000];
    explain_message_errno_tempnam(message, sizeof(message), err, dir, prefix);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

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

SEE ALSO

tempnam(3)
    create a name for a temporary file

explain_tempnam_or_die(3)
    create a name for a temporary file and report errors

COPYRIGHT
libexplain version
Copyright (C) 2009 Peter Miller