Provided by: libexplain-dev_1.4.D001-13_amd64 bug

NAME

       explain_setregid - explain setregid(2) errors

SYNOPSIS

       #include <libexplain/setregid.h>
       const char *explain_setregid(gid_t rgid, gid_t egid);
       const char *explain_errno_setregid(int errnum, gid_t rgid, gid_t egid);
       void explain_message_setregid(char *message, int message_size, gid_t rgid, gid_t egid);
       void explain_message_errno_setregid(char *message, int message_size, int errnum, gid_t
       rgid, gid_t egid);

DESCRIPTION

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

   explain_setregid
       const char *explain_setregid(gid_t rgid, gid_t egid);

       The explain_setregid function is used to obtain an explanation of an error returned by the
       setregid(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.

       rgid    The original rgid, exactly as passed to the setregid(2) system call.

       egid    The original egid, exactly as passed to the setregid(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.

       Example: This function is intended to be used  in  a  fashion  similar  to  the  following
       example:
              if (setregid(rgid, egid) < 0)
              {
                  fprintf(stderr, "%s\n", explain_setregid(rgid, egid));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_setregid
       const char *explain_errno_setregid(int errnum, gid_t rgid, gid_t egid);

       The explain_errno_setregid function is used to obtain an explanation of an error  returned
       by  the  setregid(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.

       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.

       rgid    The original rgid, exactly as passed to the setregid(2) system call.

       egid    The original egid, exactly as passed to the setregid(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.

       Example: This function is intended to be used  in  a  fashion  similar  to  the  following
       example:
              if (setregid(rgid, egid) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_setregid(err, rgid, egid));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_setregid
       void explain_message_setregid(char *message, int message_size, gid_t rgid, gid_t egid);

       The explain_message_setregid function is  used  to  obtain  an  explanation  of  an  error
       returned  by the setregid(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.

       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.

       rgid    The original rgid, exactly as passed to the setregid(2) system call.

       egid    The original egid, exactly as passed to the setregid(2) system call.

       Example: This function is intended to be used  in  a  fashion  similar  to  the  following
       example:
              if (setregid(rgid, egid) < 0)
              {
                  char message[3000];
                  explain_message_setregid(message, sizeof(message), rgid, egid);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

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

   explain_message_errno_setregid
       void explain_message_errno_setregid(char *message, int message_size, int errnum, gid_t
       rgid, gid_t egid);

       The  explain_message_errno_setregid  function is used to obtain an explanation of an error
       returned by the setregid(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.

       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.

       rgid    The original rgid, exactly as passed to the setregid(2) system call.

       egid    The original egid, exactly as passed to the setregid(2) system call.

       Example: This function is intended to be used  in  a  fashion  similar  to  the  following
       example:
              if (setregid(rgid, egid) < 0)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_setregid(message, sizeof(message), err, rgid, egid);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

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

SEE ALSO

       setregid(2)
               set real and/or effective group ID

       explain_setregid_or_die(3)
               set real and/or effective group ID and report errors

COPYRIGHT

       libexplain version 1.4
       Copyright (C) 2012 Peter Miller

                                                                              explain_setregid(3)