bionic (3) explain_raise.3.gz

Provided by: libexplain-dev_1.4.D001-7_amd64 bug

NAME

       explain_raise - explain raise(3) errors

SYNOPSIS

       #include <libexplain/raise.h>
       const char *explain_raise(int sig);
       const char *explain_errno_raise(int errnum, int sig);
       void explain_message_raise(char *message, int message_size, int sig);
       void explain_message_errno_raise(char *message, int message_size, int errnum, int sig);

DESCRIPTION

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

   explain_raise
       const char *explain_raise(int sig);

       The  explain_raise  function is used to obtain an explanation of an error returned by the raise(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.

       sig     The original sig, exactly as passed to the raise(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:
              if (raise(sig) < 0)
              {
                  fprintf(stderr, "%s\n", explain_raise(sig));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_raise
       const char *explain_errno_raise(int errnum, int sig);

       The explain_errno_raise function is used to obtain an explanation of an error returned  by  the  raise(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.

       sig     The original sig, exactly as passed to the raise(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:
              if (raise(sig) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_raise(err, sig));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_raise
       void explain_message_raise(char *message, int message_size, int sig);

       The  explain_message_raise function is used to obtain an explanation of an error returned by the raise(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.

       sig     The original sig, exactly as passed to the raise(3) system call.

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

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

   explain_message_errno_raise
       void explain_message_errno_raise(char *message, int message_size, int errnum, int sig);

       The explain_message_errno_raise function is used to obtain an explanation of an  error  returned  by  the
       raise(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.

       sig     The original sig, exactly as passed to the raise(3) system call.

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

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

SEE ALSO

       raise(3)
               send a signal to the caller

       explain_raise_or_die(3)
               send a signal to the caller and report errors

       libexplain version 1.4
       Copyright (C) 2009 Peter Miller

                                                                                                explain_raise(3)