explain_realpath_or_die(3) [debian man page]
explain_realpath_or_die(3) Library Functions Manual explain_realpath_or_die(3) NAME
explain_realpath_or_die - return canonical pathname and report errors SYNOPSIS
#include <libexplain/realpath.h> char *explain_realpath_or_die(const char *pathname, char *resolved_pathname); char *explain_realpath_on_error(const char *pathname, char *resolved_pathname); DESCRIPTION
The explain_realpath_or_die function is used to call the realpath(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_realpath(3) function, and then the process terminates by calling exit(EXIT_FAILURE). The explain_realpath_on_error function is used to call the realpath(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_realpath(3) function, but still returns to the caller. pathname The pathname, exactly as to be passed to the realpath(3) system call. resolved_pathname The resolved_pathname, exactly as to be passed to the realpath(3) system call. RETURN VALUE
The explain_realpath_or_die function only returns on success, see realpath(3) for more information. On failure, prints an explanation and exits, it does not return. The explain_realpath_on_error function always returns the value return by the wrapped realpath(3) system call. EXAMPLE
The explain_realpath_or_die function is intended to be used in a fashion similar to the following example: char *result = explain_realpath_or_die(pathname, resolved_pathname); SEE ALSO
realpath(3) return the canonicalized absolute pathname explain_realpath(3) explain realpath(3) errors exit(2) terminate the calling process COPYRIGHT
libexplain version 0.52 Copyright (C) 2011 Peter Miller explain_realpath_or_die(3)
Check Out this Related Man Page
explain_realpath(3) Library Functions Manual explain_realpath(3) NAME
explain_realpath - explain realpath(3) errors SYNOPSIS
#include <libexplain/realpath.h> const char *explain_realpath(const char *pathname, char *resolved_pathname); const char *explain_errno_realpath(int errnum, const char *pathname, char *resolved_pathname); void explain_message_realpath(char *message, int message_size, const char *pathname, char *resolved_pathname); void explain_message_errno_realpath(char *message, int message_size, int errnum, const char *pathname, char *resolved_pathname); DESCRIPTION
These functions may be used to obtain explanations for errors returned by the realpath(3) system call. explain_realpath const char *explain_realpath(const char *pathname, char *resolved_pathname); The explain_realpath function is used to obtain an explanation of an error returned by the realpath(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. pathname The original pathname, exactly as passed to the realpath(3) system call. resolved_pathname The original resolved_pathname, exactly as passed to the realpath(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: char *result = realpath(pathname, resolved_pathname); if (!result) { fprintf(stderr, "%s ", explain_realpath(pathname, resolved_pathname)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_realpath_or_die(3) function. explain_errno_realpath const char *explain_errno_realpath(int errnum, const char *pathname, char *resolved_pathname); The explain_errno_realpath function is used to obtain an explanation of an error returned by the realpath(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 neces- sary 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 realpath(3) system call. resolved_pathname The original resolved_pathname, exactly as passed to the realpath(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: char *result = realpath(pathname, resolved_pathname); if (!result) { int err = errno; fprintf(stderr, "%s ", explain_errno_realpath(err, pathname, resolved_pathname)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_realpath_or_die(3) function. explain_message_realpath void explain_message_realpath(char *message, int message_size, const char *pathname, char *resolved_pathname); The explain_message_realpath function is used to obtain an explanation of an error returned by the realpath(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. pathname The original pathname, exactly as passed to the realpath(3) system call. resolved_pathname The original resolved_pathname, exactly as passed to the realpath(3) system call. Example: This function is intended to be used in a fashion similar to the following example: char *result = realpath(pathname, resolved_pathname); if (!result) { char message[3000]; explain_message_realpath(message, sizeof(message), pathname, resolved_pathname); fprintf(stderr, "%s ", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_realpath_or_die(3) function. explain_message_errno_realpath void explain_message_errno_realpath(char *message, int message_size, int errnum, const char *pathname, char *resolved_pathname); The explain_message_errno_realpath function is used to obtain an explanation of an error returned by the realpath(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 neces- sary 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 realpath(3) system call. resolved_pathname The original resolved_pathname, exactly as passed to the realpath(3) system call. Example: This function is intended to be used in a fashion similar to the following example: char *result = realpath(pathname, resolved_pathname); if (!result) { int err = errno; char message[3000]; explain_message_errno_realpath(message, sizeof(message), err, pathname, resolved_pathname); fprintf(stderr, "%s ", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_realpath_or_die(3) function. SEE ALSO
realpath(3) return the canonicalized absolute pathname explain_realpath_or_die(3) return the canonicalized absolute pathname and report errors COPYRIGHT
libexplain version 0.52 Copyright (C) 2011 Peter Miller explain_realpath(3)