SIMPLE SOLUTIONS

EXPLAIN_FORK(3) - man page online | library functions

Explain fork(2) errors.

Chapter
explain_fork(3)                      Library Functions Manual                     explain_fork(3)

NAME

explain_fork - explain fork(2) errors

SYNOPSIS

#include <libexplain/fork.h> const char *explain_fork(void); const char *explain_errno_fork(int errnum); void explain_message_fork(char *message, int message_size); void explain_message_errno_fork(char *message, int message_size, int errnum);

DESCRIPTION

These functions may be used to obtain explanations for errors returned by the fork(2) sys‐ tem call. explain_fork const char *explain_fork(void); The explain_fork function is used to obtain an explanation of an error returned by the fork(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 (fork() < 0) { fprintf(stderr, "%s\n", explain_fork()); exit(EXIT_FAILURE); } 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 over‐ written 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_fork const char *explain_errno_fork(int errnum); The explain_errno_fork function is used to obtain an explanation of an error returned by the fork(2) system call. The least the message will contain is the value of str‐ error(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 (fork() < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_fork(err, )); 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. 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 over‐ written 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_fork void explain_message_fork(char *message, int message_size); The explain_message_fork function may be used to obtain an explanation of an error returned by the fork(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 (fork() < 0) { char message[3000]; explain_message_fork(message, sizeof(message), ); 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. explain_message_errno_fork void explain_message_errno_fork(char *message, int message_size, int errnum); The explain_message_errno_fork function may be used to obtain an explanation of an error returned by the fork(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 (fork() < 0) { int err = errno; char message[3000]; explain_message_errno_fork(message, sizeof(message), err, ); 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.

SEE ALSO

fork(2) create a child process explain_fork_or_die(3) create a child process and report errors
libexplain version 1.4 Copyright (C) 2008 Peter Miller
explain_fork(3)
This manual Reference Other manuals
explain_fork(3) referred by explain(3) | explain_fork_or_die(3)
refer to explain_fork_or_die(3) | fork(2)