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EXPLAIN_EXECVE - reference manual online

Explain execve(2) errors.

Chapter
explain_execve(3)                    Library Functions Manual                   explain_execve(3)

NAME explain_execve - explain execve(2) errors
SYNOPSIS #include <libexplain/execve.h> const char *explain_execve(const char *pathname, const char *const *argv, const char *const *envp); const char *explain_errno_execve(int errnum, const char *pathname, const char *const *argv, const char *const *envp); void explain_message_execve(char *message, int message_size, const char *pathname, const char *const *argv, const char *const *envp); void explain_message_errno_execve(char *message, int message_size, int errnum, const char *pathname, const char *const *argv, const char *const *envp);
DESCRIPTION These functions may be used to obtain explanations for errors returned by the execve(2) system call. explain_execve const char *explain_execve(const char *pathname, const char *const *argv, const char *const *envp); The explain_execve function is used to obtain an explanation of an error returned by the execve(2) system call. The least the message will contain is the value of str‐ error(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: execve(pathname, argv, envp); fprintf(stderr, "%s\n", explain_execve(pathname, argv, envp)); exit(EXIT_FAILURE); pathname The original pathname, exactly as passed to the execve(2) system call. argv The original argv, exactly as passed to the execve(2) system call. envp The original envp, exactly as passed to the execve(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 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_execve const char *explain_errno_execve(int errnum, const char *pathname, const char *const *argv, const char *const *envp); The explain_errno_execve function is used to obtain an explanation of an error returned by the execve(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: execve(pathname, argv, envp); int err = errno; fprintf(stderr, "%s\n", explain_errno_execve(err, pathname, argv, envp)); 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 execve(2) system call. argv The original argv, exactly as passed to the execve(2) system call. envp The original envp, exactly as passed to the execve(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 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_execve void explain_message_execve(char *message, int message_size, const char *pathname, const char *const *argv, const char *const *envp); The explain_message_execve function may be used to obtain an explanation of an error returned by the execve(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: execve(pathname, argv, envp); char message[3000]; explain_message_execve(message, sizeof(message), pathname, argv, envp); 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 execve(2) system call. argv The original argv, exactly as passed to the execve(2) system call. envp The original envp, exactly as passed to the execve(2) system call. explain_message_errno_execve void explain_message_errno_execve(char *message, int message_size, int errnum, const char *pathname, const char *const *argv, const char *const *envp); The explain_message_errno_execve function may be used to obtain an explanation of an error returned by the execve(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: execve(pathname, argv, envp); int err = errno; char message[3000]; explain_message_errno_execve(message, sizeof(message), err, pathname, argv, envp); 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 execve(2) system call. argv The original argv, exactly as passed to the execve(2) system call. envp The original envp, exactly as passed to the execve(2) system call.
SEE ALSO execve(2) execute program explain_execve_or_die(3) execute program and report errors
explain_execve(3)
This manual Reference Other manuals
explain_execve(3) referred by explain(3) | explain_execve_or_die(3)
refer to execve(2) | explain_execve_or_die(3)