explain_puts(3) Library Functions Manual explain_puts(3) NAME explain_puts - explain puts(3) errors SYNOPSIS #include <libexplain/puts.h> const char *explain_puts(const char *s); const char *explain_errno_puts(int errnum, const char *s); void explain_message_puts(char *message, int message_size, const char *s); void explain_message_errno_puts(char *message, int message_size, int er- rnum, const char *s); DESCRIPTION These functions may be used to obtain explanations for errors returned by the puts(3) system call. explain_puts const char *explain_puts(const char *s); The explain_puts function is used to obtain an explanation of an error re- turned by the puts(3) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indi- cate the underlying cause in more detail. The errno global variable will be used to obtain the error value to be de- coded. s The original s, exactly as passed to the puts(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 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 (puts(s) < 0) { fprintf(stderr, "%s\n", explain_puts(s)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the ex- plain_puts_or_die(3) function. explain_errno_puts const char *explain_errno_puts(int errnum, const char *s); The explain_errno_puts function is used to obtain an explanation of an er- ror returned by the puts(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 ex- plained and this function, because many libc functions will alter the value of errno. s The original s, exactly as passed to the puts(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 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 (puts(s) < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_puts(err, s)); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the ex- plain_puts_or_die(3) function. explain_message_puts void explain_message_puts(char *message, int message_size, const char *s); The explain_message_puts function is used to obtain an explanation of an error returned by the puts(3) system call. The least the message will con- tain 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. 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. s The original s, exactly as passed to the puts(3) system call. Example: This function is intended to be used in a fashion similar to the following example: if (puts(s) < 0) { char message[3000]; explain_message_puts(message, sizeof(message), s); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the ex- plain_puts_or_die(3) function. explain_message_errno_puts void explain_message_errno_puts(char *message, int message_size, int er- rnum, const char *s); The explain_message_errno_puts function is used to obtain an explanation of an error returned by the puts(3) 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. 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. s The original s, exactly as passed to the puts(3) system call. Example: This function is intended to be used in a fashion similar to the following example: if (puts(s) < 0) { int err = errno; char message[3000]; explain_message_errno_puts(message, sizeof(message), err, s); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } The above code example is available pre-packaged as the ex- plain_puts_or_die(3) function. SEE ALSO puts(3) write a string and a trailing newline to stdout explain_puts_or_die(3) write a string and a trailing newline to stdout and report errors COPYRIGHT libexplain version 1.3 Copyright (C) 2009 Peter Miller explain_puts(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT
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