bionic (3) explain_strtold.3.gz
NAME
explain_strtold - explain strtold(3) errors
SYNOPSIS
#include <libexplain/strtold.h>
const char *explain_strtold(const char *nptr, char **endptr);
const char *explain_errno_strtold(int errnum, const char *nptr, char **endptr);
void explain_message_strtold(char *message, int message_size, const char *nptr, char **endptr);
void explain_message_errno_strtold(char *message, int message_size, int errnum, const char *nptr, char
**endptr);
DESCRIPTION
These functions may be used to obtain explanations for errors returned by the strtold(3) system call. explain_strtold const char *explain_strtold(const char *nptr, char **endptr); The explain_strtold function is used to obtain an explanation of an error returned by the strtold(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. nptr The original nptr, exactly as passed to the strtold(3) system call. endptr The original endptr, exactly as passed to the strtold(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: long double result = strtold(nptr, endptr); if (result < 0) { fprintf(stderr, "%s\n", explain_strtold(nptr, endptr)); exit(EXIT_FAILURE); } The above code example is available pre‐packaged as the explain_strtold_or_die(3) function. explain_errno_strtold const char *explain_errno_strtold(int errnum, const char *nptr, char **endptr); The explain_errno_strtold function is used to obtain an explanation of an error returned by the strtold(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 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. nptr The original nptr, exactly as passed to the strtold(3) system call. endptr The original endptr, exactly as passed to the strtold(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: long double result = strtold(nptr, endptr); if (result < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_strtold(err, nptr, endptr)); exit(EXIT_FAILURE); } The above code example is available pre‐packaged as the explain_strtold_or_die(3) function. explain_message_strtold void explain_message_strtold(char *message, int message_size, const char *nptr, char **endptr); The explain_message_strtold function is used to obtain an explanation of an error returned by the strtold(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. nptr The original nptr, exactly as passed to the strtold(3) system call. endptr The original endptr, exactly as passed to the strtold(3) system call. Example: This function is intended to be used in a fashion similar to the following example: long double result = strtold(nptr, endptr); if (result < 0) { char message[3000]; explain_message_strtold(message, sizeof(message), nptr, endptr); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre‐packaged as the explain_strtold_or_die(3) function. explain_message_errno_strtold void explain_message_errno_strtold(char *message, int message_size, int errnum, const char *nptr, char **endptr); The explain_message_errno_strtold function is used to obtain an explanation of an error returned by the strtold(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 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. nptr The original nptr, exactly as passed to the strtold(3) system call. endptr The original endptr, exactly as passed to the strtold(3) system call. Example: This function is intended to be used in a fashion similar to the following example: long double result = strtold(nptr, endptr); if (result < 0) { int err = errno; char message[3000]; explain_message_errno_strtold(message, sizeof(message), err, nptr, endptr); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre‐packaged as the explain_strtold_or_die(3) function.
SEE ALSO
strtold(3) convert ASCII string to floating‐point number explain_strtold_or_die(3) convert ASCII string to floating‐point number and report errors
COPYRIGHT
libexplain version 1.4
Copyright (C) 2009 Peter Miller
explain_strtold(3)