explain_setvbuf_or_die(3) [debian man page]
explain_setvbuf_or_die(3) Library Functions Manual explain_setvbuf_or_die(3) NAME
explain_setvbuf_or_die - stream buffering operations and report errors SYNOPSIS
#include <libexplain/setvbuf.h> void explain_setvbuf_or_die(FILE *fp, char *data, int mode, size_t size); int explain_setvbuf_on_error(FILE *fp, char *data, int mode, size_t size); DESCRIPTION
The explain_setvbuf_or_die function is used to call the setvbuf(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_setvbuf(3) function, and then the process terminates by calling exit(EXIT_FAILURE). The explain_setvbuf_on_error function is used to call the setvbuf(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_setvbuf(3) function, but still returns to the caller. fp The fp, exactly as to be passed to the setvbuf(3) system call. data The data, exactly as to be passed to the setvbuf(3) system call. mode The mode, exactly as to be passed to the setvbuf(3) system call. size The size, exactly as to be passed to the setvbuf(3) system call. RETURN VALUE
The explain_setvbuf_or_die function only returns on success, see setvbuf(3) for more information. On failure, prints an explanation and exits, it does not return. The explain_setvbuf_on_error function always returns the value return by the wrapped setvbuf(3) system call. EXAMPLE
The explain_setvbuf_or_die function is intended to be used in a fashion similar to the following example: explain_setvbuf_or_die(fp, data, mode, size); SEE ALSO
setvbuf(3) stream buffering operations explain_setvbuf(3) explain setvbuf(3) errors exit(2) terminate the calling process COPYRIGHT
libexplain version 0.52 Copyright (C) 2010 Peter Miller explain_setvbuf_or_die(3)
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explain_setvbuf(3) Library Functions Manual explain_setvbuf(3) NAME
explain_setvbuf - explain setvbuf(3) errors SYNOPSIS
#include <libexplain/setvbuf.h> const char *explain_setvbuf(FILE *fp, char *data, int mode, size_t size); const char *explain_errno_setvbuf(int errnum, FILE *fp, char *data, int mode, size_t size); void explain_message_setvbuf(char *message, int message_size, FILE *fp, char *data, int mode, size_t size); void explain_message_errno_setvbuf(char *message, int message_size, int errnum, FILE *fp, char *data, int mode, size_t size); DESCRIPTION
These functions may be used to obtain explanations for errors returned by the setvbuf(3) system call. explain_setvbuf const char *explain_setvbuf(FILE *fp, char *data, int mode, size_t size); The explain_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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. fp The original fp, exactly as passed to the setvbuf(3) system call. data The original data, exactly as passed to the setvbuf(3) system call. mode The original mode, exactly as passed to the setvbuf(3) system call. size The original size, exactly as passed to the setvbuf(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: if (setvbuf(fp, data, mode, size) < 0) { fprintf(stderr, "%s ", explain_setvbuf(fp, data, mode, size)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_setvbuf_or_die(3) function. explain_errno_setvbuf const char *explain_errno_setvbuf(int errnum, FILE *fp, char *data, int mode, size_t size); The explain_errno_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(3) system call. The least the mes- sage 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. fp The original fp, exactly as passed to the setvbuf(3) system call. data The original data, exactly as passed to the setvbuf(3) system call. mode The original mode, exactly as passed to the setvbuf(3) system call. size The original size, exactly as passed to the setvbuf(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: if (setvbuf(fp, data, mode, size) < 0) { int err = errno; fprintf(stderr, "%s ", explain_errno_setvbuf(err, fp, data, mode, size)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_setvbuf_or_die(3) function. explain_message_setvbuf void explain_message_setvbuf(char *message, int message_size, FILE *fp, char *data, int mode, size_t size); The explain_message_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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. fp The original fp, exactly as passed to the setvbuf(3) system call. data The original data, exactly as passed to the setvbuf(3) system call. mode The original mode, exactly as passed to the setvbuf(3) system call. size The original size, exactly as passed to the setvbuf(3) system call. Example: This function is intended to be used in a fashion similar to the following example: if (setvbuf(fp, data, mode, size) < 0) { char message[3000]; explain_message_setvbuf(message, sizeof(message), fp, data, mode, size); fprintf(stderr, "%s ", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_setvbuf_or_die(3) function. explain_message_errno_setvbuf void explain_message_errno_setvbuf(char *message, int message_size, int errnum, FILE *fp, char *data, int mode, size_t size); The explain_message_errno_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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. fp The original fp, exactly as passed to the setvbuf(3) system call. data The original data, exactly as passed to the setvbuf(3) system call. mode The original mode, exactly as passed to the setvbuf(3) system call. size The original size, exactly as passed to the setvbuf(3) system call. Example: This function is intended to be used in a fashion similar to the following example: if (setvbuf(fp, data, mode, size) < 0) { int err = errno; char message[3000]; explain_message_errno_setvbuf(message, sizeof(message), err, fp, data, mode, size); fprintf(stderr, "%s ", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the explain_setvbuf_or_die(3) function. SEE ALSO
setvbuf(3) stream buffering operations explain_setvbuf_or_die(3) stream buffering operations and report errors COPYRIGHT
libexplain version 0.52 Copyright (C) 2010 Peter Miller explain_setvbuf(3)