explain_fstatat(3) Library Functions Manual explain_fstatat(3) NAME explain_fstatat - explain fstatat(2) errors SYNOPSIS #include <libexplain/fstatat.h> const char *explain_fstatat(int fildes, const char *pathname, struct stat *data, int flags); const char *explain_errno_fstatat(int errnum, int fildes, const char *path- name, struct stat *data, int flags); void explain_message_fstatat(char *message, int message_size, int fildes, const char *pathname, struct stat *data, int flags); void explain_message_errno_fstatat(char *message, int message_size, int er- rnum, int fildes, const char *pathname, struct stat *data, int flags); DESCRIPTION These functions may be used to obtain explanations for errors returned by the fstatat(2) system call. explain_fstatat const char *explain_fstatat(int fildes, const char *pathname, struct stat *data, int flags); The explain_fstatat function is used to obtain an explanation of an error returned by the fstatat(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 de- coded. fildes The original fildes, exactly as passed to the fstatat(2) system call. pathname The original pathname, exactly as passed to the fstatat(2) system call. data The original data, exactly as passed to the fstatat(2) system call. flags The original flags, exactly as passed to the fstatat(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 ar- gument list. This will be overwritten by the next call to any lib- explain 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 (fstatat(fildes, pathname, data, flags) < 0) { fprintf(stderr, "%s\n", explain_fstatat(fildes, pathname, data, flags)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_fs- tatat_or_die(3) function. explain_errno_fstatat const char *explain_errno_fstatat(int errnum, int fildes, const char *path- name, struct stat *data, int flags); The explain_errno_fstatat function is used to obtain an explanation of an error returned by the fstatat(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much bet- ter, 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 neces- sary if you need to call any code between the system call to be ex- plained and this function, because many libc functions will alter the value of errno. fildes The original fildes, exactly as passed to the fstatat(2) system call. pathname The original pathname, exactly as passed to the fstatat(2) system call. data The original data, exactly as passed to the fstatat(2) system call. flags The original flags, exactly as passed to the fstatat(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 ar- gument list. This will be overwritten by the next call to any lib- explain 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 (fstatat(fildes, pathname, data, flags) < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_fstatat(err, fildes, path- name, data, flags)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_fs- tatat_or_die(3) function. explain_message_fstatat void explain_message_fstatat(char *message, int message_size, int fildes, const char *pathname, struct stat *data, int flags); The explain_message_fstatat function is used to obtain an explanation of an error returned by the fstatat(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much bet- ter, and indicate the underlying cause in more detail. The errno global variable will be used to obtain the error value to be de- coded. 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. fildes The original fildes, exactly as passed to the fstatat(2) system call. pathname The original pathname, exactly as passed to the fstatat(2) system call. data The original data, exactly as passed to the fstatat(2) system call. flags The original flags, exactly as passed to the fstatat(2) system call. Example: This function is intended to be used in a fashion similar to the following example: if (fstatat(fildes, pathname, data, flags) < 0) { char message[3000]; explain_message_fstatat(message, sizeof(message), fildes, path- name, data, flags); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_fs- tatat_or_die(3) function. explain_message_errno_fstatat void explain_message_errno_fstatat(char *message, int message_size, int er- rnum, int fildes, const char *pathname, struct stat *data, int flags); The explain_message_errno_fstatat function is used to obtain an explanation of an error returned by the fstatat(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 neces- sary if you need to call any code between the system call to be ex- plained and this function, because many libc functions will alter the value of errno. fildes The original fildes, exactly as passed to the fstatat(2) system call. pathname The original pathname, exactly as passed to the fstatat(2) system call. data The original data, exactly as passed to the fstatat(2) system call. flags The original flags, exactly as passed to the fstatat(2) system call. Example: This function is intended to be used in a fashion similar to the following example: if (fstatat(fildes, pathname, data, flags) < 0) { int err = errno; char message[3000]; explain_message_errno_fstatat(message, sizeof(message), err, fildes, pathname, data, flags); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_fs- tatat_or_die(3) function. SEE ALSO fstatat(2) get file status relative to a directory file descriptor explain_fstatat_or_die(3) get file status relative to a directory file descriptor and report errors COPYRIGHT libexplain version 1.3 Copyright (C) 2013 Peter Miller explain_fstatat(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT
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