Provided by: libexplain-dev_1.4.D001-8_amd64 bug

NAME

       explain_realloc - explain realloc(3) errors

SYNOPSIS

       #include <libexplain/realloc.h>
       const char *explain_realloc(void *ptr, size_t size);
       const char *explain_errno_realloc(int errnum, void *ptr, size_t size);
       void explain_message_realloc(char *message, int message_size, void *ptr, size_t size);
       void explain_message_errno_realloc(char *message, int message_size, int errnum, void *ptr,
       size_t size);

DESCRIPTION

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

   explain_realloc
       const char *explain_realloc(void *ptr, size_t size);

       The  explain_realloc function is used to obtain an explanation of an error returned by the
       realloc(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.

       This function is intended to be used in a fashion similar to the following example:
              void *new_ptr = realloc(ptr, size);
              if (!new_ptr)
              {
                  fprintf(stderr, "%s\n", explain_realloc(ptr, size));
                  exit(EXIT_FAILURE);
              }

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

       ptr     The original ptr, exactly as passed to the realloc(3) system call.

       size    The original size, exactly as passed to the realloc(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.

   explain_errno_realloc
       const char *explain_errno_realloc(int errnum, void *ptr, size_t size);

       The  explain_errno_realloc  function is used to obtain an explanation of an error returned
       by the realloc(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.

       This function is intended to be used in a fashion similar to the following example:
              void *new_ptr = realloc(ptr, size);
              if (!new_ptr)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_realloc(err, ptr, size));
                  exit(EXIT_FAILURE);
              }

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

       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.

       ptr     The original ptr, exactly as passed to the realloc(3) system call.

       size    The original size, exactly as passed to the realloc(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.

   explain_message_realloc
       void explain_message_realloc(char *message, int message_size, void *ptr, size_t size);

       The explain_message_realloc function may be used to  obtain an  explanation  of  an  error
       returned  by  the realloc(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.

       This function is intended to be used in a fashion similar to the following example:
              void *new_ptr = realloc(ptr, size);
              if (!new_ptr)
              {
                  char message[3000];
                  explain_message_realloc(message, sizeof(message), ptr, size);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

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

       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.

       ptr     The original ptr, exactly as passed to the realloc(3) system call.

       size    The original size, exactly as passed to the realloc(3) system call.

   explain_message_errno_realloc
       void explain_message_errno_realloc(char *message, int message_size, int errnum, void *ptr,
       size_t size);

       The explain_message_errno_realloc function may be used to  obtain  an  explanation  of  an
       error  returned  by the realloc(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.

       This function is intended to be used in a fashion similar to the following example:
              void *new_ptr = realloc(ptr, size);
              if (!new_ptr)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_realloc(message, sizeof(message), err, ptr, size);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

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

       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.

       ptr     The original ptr, exactly as passed to the realloc(3) system call.

       size    The original size, exactly as passed to the realloc(3) system call.

SEE ALSO

       realloc(3)
               Allocate and free dynamic memory

       explain_realloc_or_die(3)
               Allocate and free dynamic memory and report errors

COPYRIGHT

       libexplain version 1.4
       Copyright (C) 2009 Peter Miller

                                                                               explain_realloc(3)