explain_program_name(3) [debian man page]
explain_program_name(3) Library Functions Manual explain_program_name(3) NAME
explain_program_name - manipulate the program name SYNOPSIS
#include <libexplain/libexplain.h> const char *explain_program_name_get(void); void explain_program_name_set(const char *name); void explain_program_name_assemble(int yesno); DESCRIPTION
These functions may be used to manipulate libexplain's idea of the command name of the current process, and whether or not that name is included in error messages. explain_program_name_get const char *explain_program_name_get(void); The explain_program_name_get function may be used to obtain the command name of the calling process. Depending on how capable /proc is on your system, or, failing that, how capable lsof(1) is on your system, this may or may not produce a sensible result. It works well on Linux. Returns: pointer to string containing the command name (no slashes) of the calling process. explain_program_name_set void explain_program_name_set(const char *name); The explain_program_name_set function may be used to set the libexplain libraries' idea of the command name of the calling process, setting the string to be returned by the explain_program_name_get(3) function. This overrides the automatic behavior, which can be quite desirable in commands that can be invoked with more than one name, e.g. if they are a hard link synonym. This also sets the option to include the program name in all of the error messages issued by the explain_*_or_die(3) functions. name The name of the calling process. Only the basename will be used if a path containing slashes is given. explain_program_name_assemble void explain_program_name_assemble(int yesno); The explain_program_name_assemble function is used to control whether or not the name of the calling process is to be included in error messages issued by the explain_*_or_die(3) functions. If not explicitly set, is controlled by the EXPLAIN_OPTIONS environment variable, or defaults to true if not set there either. yesno non-zero (true) to have program name included, zero (false) to have program name excluded. COPYRIGHT
libexplain version 0.52 Copyright (C) 2008 Peter Miller AUTHOR
Written by Peter Miller <pmiller@opensource.org.au> explain_program_name(3)
Check Out this Related Man Page
explain_fopen(3) Library Functions Manual explain_fopen(3) NAME
explain_fopen - explain fopen(3) errors SYNOPSIS
#include <libexplain/fopen.h> const char *explain_fopen(const char *path, const char *mode); const char *explain_errno_fopen(int errnum, const char *path, const char *mode); void explain_message_fopen(char *message, int message_size, const char *path, const char *mode); void explain_message_errno_fopen(char *message, int message_size, int errnum, const char *path, const char *mode); DESCRIPTION
These functions may be used to obtain explanations for fopen(3) errors. explain_fopen const char *explain_fopen(const char *path, const char *mode); The explain_fopen function is used to obtain an explanation of an error returned by the fopen(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. This function is intended to be used in a fashion similar to the following example: FILE *fp = fopen(path, mode); if (!fp) { const char *message = explain_fopen(path, mode); fprintf(stderr, '%s0, message); exit(EXIT_FAILURE); } path The original path, exactly as passed to the fopen(3) system call. mode The original mode, exactly as passed to the fopen(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. explain_errno_fopen const char *explain_errno_fopen(int errnum, const char *path, const char *mode); The explain_errno_fopen function is used to obtain an explanation of an error returned by the fopen(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. This function is intended to be used in a fashion similar to the following example: FILE *fp = fopen(path, mode); if (!fp) { const char *message = explain_errno_fopen(err, path, mode); fprintf(stderr, '%s0, message); exit(EXIT_FAILURE); } 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. path The original path, exactly as passed to the fopen(3) system call. mode The original mode, exactly as passed to the fopen(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. explain_message_fopen void explain_message_fopen(char *message, int message_size, const char *path, const char *mode); The explain_message_fopen function is used to obtain an explanation of an error returned by the fopen(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. This function is intended to be used in a fashion similar to the following example: FILE *fp = fopen(path, mode); if (!fp) { char message[3000]; explain_message_fopen(message, sizeof(message), path, mode); fprintf(stderr, '%s0, message); exit(EXIT_FAILURE); } message The location in which to store the returned message. Because a message return buffer has been supplied, this function is thread safe. message_size The size in bytes of the location in which to store the returned message. path The original path, exactly as passed to the fopen(3) system call. mode The original mode, exactly as passed to the fopen(3) system call explain_message_errno_fopen void explain_message_errno_fopen(char *message, int message_size, int errnum, const char *path, const char *mode); The explain_message_errno_fopen function is used to obtain an explanation of an error returned by the fopen(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. This function is intended to be used in a fashion similar to the following example: FILE *fp = fopen(path, mode); if (!fp) { int err = errno; char message[3000]; explain_message_errno_fopen(message, sizeof(message), err, path, mode); fprintf(stderr, '%s0, message); exit(EXIT_FAILURE); } message The location in which to store the returned message. Because a message return buffer has been 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. path The original path, exactly as passed to the fopen(3) system call. mode The original mode, exactly as passed to the fopen(3) system call. COPYRIGHT
libexplain version 0.52 Copyright (C) 2008 Peter Miller AUTHOR
Written by Peter Miller <pmiller@opensource.org.au> explain_fopen(3)