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

NAME

       explain_readlink - explain readlink(2) errors

SYNOPSIS

       #include <libexplain/readlink.h>
       const char *explain_readlink(const char *pathname, char *data, size_t data_size);
       const  char  *explain_errno_readlink(int  errnum, const char *pathname, char *data, size_t
       data_size);
       void explain_message_readlink(char *message, int message_size, const char *pathname,  char
       *data, size_t data_size);
       void  explain_message_errno_readlink(char  *message,  int  message_size, int errnum, const
       char *pathname, char *data, size_t data_size);

DESCRIPTION

       These functions may be used to obtain explanations for errors returned by the  readlink(2)
       system call.

   explain_readlink
       const char *explain_readlink(const char *pathname, char *data, size_t data_size);

       The explain_readlink function is used to obtain an explanation of an error returned by the
       readlink(2)  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:
              if (readlink(pathname, data, data_size) < 0)
              {
                  fprintf(stderr, "%s\n", explain_readlink(pathname, data, data_size));
                  exit(EXIT_FAILURE);
              }

       pathname
               The original pathname, exactly as passed to the readlink(2) system call.

       data    The original data, exactly as passed to the readlink(2) system call.

       data_size
               The original data_size, exactly as passed to the readlink(2) 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_readlink
       const char *explain_errno_readlink(int errnum, const char *pathname,  char  *data,  size_t
       data_size);

       The  explain_errno_readlink function is used to obtain an explanation of an error returned
       by the readlink(2) 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:
              if (readlink(pathname, data, data_size) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_readlink(err, pathname, data,
                      data_size));
                  exit(EXIT_FAILURE);
              }

       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.

       pathname
               The original pathname, exactly as passed to the readlink(2) system call.

       data    The original data, exactly as passed to the readlink(2) system call.

       data_size
               The original data_size, exactly as passed to the readlink(2) 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_readlink
       void  explain_message_readlink(char *message, int message_size, const char *pathname, char
       *data, size_t data_size);

       The explain_message_readlink function may be used to  obtain an explanation  of  an  error
       returned  by the readlink(2) 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:
              if (readlink(pathname, data, data_size) < 0)
              {
                  char message[3000];
                  explain_message_readlink(message, sizeof(message), pathname, data,
                      data_size);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       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.

       pathname
               The original pathname, exactly as passed to the readlink(2) system call.

       data    The original data, exactly as passed to the readlink(2) system call.

       data_size
               The original data_size, exactly as passed to the readlink(2) system call.

   explain_message_errno_readlink
       void explain_message_errno_readlink(char *message, int  message_size,  int  errnum,  const
       char *pathname, char *data, size_t data_size);

       The  explain_message_errno_readlink  function  may  be used to obtain an explanation of an
       error returned by the readlink(2) 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:
              if (readlink(pathname, data, data_size) < 0)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_readlink(message, sizeof(message), err, pathname,
                      data, data_size);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       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.

       pathname
               The original pathname, exactly as passed to the readlink(2) system call.

       data    The original data, exactly as passed to the readlink(2) system call.

       data_size
               The original data_size, exactly as passed to the readlink(2) system call.

SEE ALSO

       readlink(2)
               blah blah blah

       explain_readlink_or_die(3)
               blah blah blah  and report errors

COPYRIGHT

       libexplain version 1.4
       Copyright (C) 2008 Peter Miller

                                                                              explain_readlink(3)