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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 er- ror 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 fol- lowing 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) sys- tem 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 overwritten by the next call to any libexplain function which shares this buffer, in- cluding 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 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 fol- lowing 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) sys- tem 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 overwritten by the next call to any libexplain function which shares this buffer, in- cluding 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 explana- tion 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 fol- lowing 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 re- turned message. pathname The original pathname, exactly as passed to the execve(2) sys- tem 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 ex- planation 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 de- tail. This function is intended to be used in a fashion similar to the fol- lowing 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 re- turned 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) sys- tem 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 COPYRIGHT libexplain version 1.3 Copyright (C) 2008 Peter Miller explain_execve(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT
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