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explain_uname(3) Library Functions Manual explain_uname(3) NAME explain_uname - explain uname(2) errors SYNOPSIS #include <libexplain/uname.h> const char *explain_uname(struct utsname *data); const char *explain_errno_uname(int errnum, struct utsname *data); void explain_message_uname(char *message, int message_size, struct ut- sname *data); void explain_message_errno_uname(char *message, int message_size, int errnum, struct utsname *data); DESCRIPTION These functions may be used to obtain explanations for errors returned by the uname(2) system call. explain_uname const char *explain_uname(struct utsname *data); The explain_uname function is used to obtain an explanation of an error returned by the uname(2) system call. The least the message will con- tain 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 decoded. data The original data, exactly as passed to the uname(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, 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 (uname(data) < 0) { fprintf(stderr, "%s\n", explain_uname(data)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_un- ame_or_die(3) function. explain_errno_uname const char *explain_errno_uname(int errnum, struct utsname *data); The explain_errno_uname function is used to obtain an explanation of an error returned by the uname(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. 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. data The original data, exactly as passed to the uname(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, 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 (uname(data) < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_uname(err, data)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_un- ame_or_die(3) function. explain_message_uname void explain_message_uname(char *message, int message_size, struct ut- sname *data); The explain_message_uname function is used to obtain an explanation of an error returned by the uname(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. message The location in which to store the returned message. If a suit- able 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. data The original data, exactly as passed to the uname(2) system call. Example: This function is intended to be used in a fashion similar to the following example: if (uname(data) < 0) { char message[3000]; explain_message_uname(message, sizeof(message), data); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_un- ame_or_die(3) function. explain_message_errno_uname void explain_message_errno_uname(char *message, int message_size, int errnum, struct utsname *data); The explain_message_errno_uname function is used to obtain an explana- tion of an error returned by the uname(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 suit- able 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. data The original data, exactly as passed to the uname(2) system call. Example: This function is intended to be used in a fashion similar to the following example: if (uname(data) < 0) { int err = errno; char message[3000]; explain_message_errno_uname(message, sizeof(message), err, data); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_un- ame_or_die(3) function. SEE ALSO uname(2) get name and information about current kernel explain_uname_or_die(3) get name and information about current kernel and report errors COPYRIGHT libexplain version 1.3 Copyright (C) 2013 Peter Miller explain_uname(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT
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