libexplain  1.4.D001
Functions
libexplain/calloc.c File Reference
#include <libexplain/ac/errno.h>
#include <libexplain/ac/stdlib.h>
#include <libexplain/buffer/errno/calloc.h>
#include <libexplain/calloc.h>
#include <libexplain/common_message_buffer.h>

Go to the source code of this file.

Functions

const char * explain_calloc (size_t nmemb, size_t size)
const char * explain_errno_calloc (int errnum, size_t nmemb, size_t size)
void explain_message_calloc (char *message, int message_size, size_t nmemb, size_t size)
void explain_message_errno_calloc (char *message, int message_size, int errnum, size_t nmemb, size_t size)

Function Documentation

const char* explain_calloc ( size_t  nmemb,
size_t  size 
)

The explain_calloc function is used to obtain an explanation of an error returned by the calloc(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.

Parameters:
nmembThe original nmemb, exactly as passed to the calloc(3) system call.
sizeThe original size, exactly as passed to the calloc(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:
 errno = 0;
 void *result = calloc(nmemb, size);
 if (!result && errno != 0)
 {
     fprintf(stderr, "%s\n", explain_calloc(nmemb, size));
     exit(EXIT_FAILURE);
 }
The above code example is available pre\-packaged as the explain_calloc_or_die function.

Definition at line 28 of file calloc.c.

const char* explain_errno_calloc ( int  errnum,
size_t  nmemb,
size_t  size 
)

The explain_errno_calloc function is used to obtain an explanation of an error returned by the calloc(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.

Parameters:
errnumThe 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.
nmembThe original nmemb, exactly as passed to the calloc(3) system call.
sizeThe original size, exactly as passed to the calloc(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:
 errno = 0;
 void *result = calloc(nmemb, size);
 if (!result && errno != 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_calloc(err, nmemb, size));
     exit(EXIT_FAILURE);
 }
The above code example is available pre-packaged as the explain_calloc_or_die function.

Definition at line 35 of file calloc.c.

void explain_message_calloc ( char *  message,
int  message_size,
size_t  nmemb,
size_t  size 
)

Definition at line 44 of file calloc.c.

void explain_message_errno_calloc ( char *  message,
int  message_size,
int  errnum,
size_t  nmemb,
size_t  size 
)

Definition at line 52 of file calloc.c.