explain pclose(3) errors More...

#include <libexplain/large_file_support.h>
#include <libexplain/gcc_attributes.h>
#include <stdio.h>

Functions
int	explain_pclose_or_die (FILE *fp)
int	explain_pclose_on_error (FILE *fp) LIBEXPLAIN_WARN_UNUSED_RESULT
int	explain_pclose_success (FILE *fp)
void	explain_pclose_success_or_die (FILE *fp)
const char *	explain_pclose (FILE *fp) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_errno_pclose (int errnum, FILE *fp) LIBEXPLAIN_WARN_UNUSED_RESULT
void	explain_message_pclose (char message, int message_size, FILE fp)
void	explain_message_errno_pclose (char message, int message_size, int errnum, FILE fp)

Detailed Description

explain pclose(3) errors

Definition in file pclose.h.

Function Documentation

const char* explain_errno_pclose	(	int	errnum,
		FILE *	fp
	)

The explain_errno_pclose function is used to obtain an explanation of an error returned by the pclose(3) system call. The least the message will contain is the value of strerror(errnum), 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:

 int result = pclose(fp);
 if (result < 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_pclose(err, fp));
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_pclose_or_die function.

Parameters:

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.
fp	The original fp, exactly as passed to the pclose(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.

void explain_message_errno_pclose	(	char *	message,
		int	message_size,
		int	errnum,
		FILE *	fp
	)

The explain_message_errno_pclose function is used to obtain an explanation of an error returned by the pclose(3) system call. The least the message will contain is the value of strerror(errnum), 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:

 int result = pclose(fp);
 if (result < 0)
 {
     int err = errno;
     char message[3000];
     explain_message_errno_pclose(message, sizeof(message), err, fp);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_pclose_or_die function.

Parameters:

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.
fp	The original fp, exactly as passed to the pclose(3) system call.

void explain_message_pclose	(	char *	message,
		int	message_size,
		FILE *	fp
	)

The explain_message_pclose function is used to obtain an explanation of an error returned by the pclose(3) system call. The least the message will contain is the value of strerror(errnum), 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:

 int result = pclose(fp);
 if (result < 0)
 {
     char message[3000];
     explain_message_pclose(message, sizeof(message), fp);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_pclose_or_die function.

Parameters:

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 pclose(3) system call.

const char* explain_pclose ( FILE * fp )

The explain_pclose function is used to obtain an explanation of an error returned by the pclose(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:

 int result = pclose(fp);
 if (result < 0)
 {
     fprintf(stderr, "%s\n", explain_pclose(fp));
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_pclose_or_die function.

Parameters:

fp	The original fp, exactly as passed to the pclose(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.

int explain_pclose_on_error ( FILE * fp )

The explain_pclose_on_error function is used to call the pclose(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_pclose(3) function.

This function is intended to be used in a fashion similar to the following example:

 int result = explain_pclose_on_error(fp);
 if (result < 0)
 {
     ...cope with error
     ...no need to print error message
 }

Parameters:

fp	The fp, exactly as to be passed to the pclose(3) system call.

Returns:: The value returned by the wrapped pclose(3) system call.

int explain_pclose_or_die ( FILE * fp )

The explain_pclose_or_die function is used to call the pclose(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_pclose(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

This function is intended to be used in a fashion similar to the following example:

 int result = explain_pclose_or_die(fp);

Parameters:

fp	The fp, exactly as to be passed to the pclose(3) system call.

Returns:: This function only returns on success. On failure, prints an explanation and exits, it does not return.

int explain_pclose_success ( FILE * fp )

The explain_pclose_success function is used to call the pclose(3) system call. On failure (including any exit status other than EXIT_SUCCESS) an explanation will be printed to stderr, obtained from explain_pclose(3). The return value from pclose(3) is returned.

This function is intended to be used in a fashion similar to the following example:

 int result = explain_pclose_success(fp);

Parameters:

fp	The fp, exactly as to be passed to the pclose(3) pclose call.

Returns:: the value returned by the pclose(3) pclose call.

void explain_pclose_success_or_die ( FILE * fp )

The explain_pclose_success_or_die function is used to call the pclose(3) system call. On failure (including any exit status other than EXIT_SUCCESS) an explanation will be printed to stderr, obtained from explain_pclose(3), and then the process terminates by calling exit(EXIT_FAILURE).

This function is intended to be used in a fashion similar to the following example:

 explain_pclose_success_or_die(fp);

Parameters:

fp	The fp, exactly as to be passed to the pclose(3) pclose call.

Returns:: This function only returns on success (exit status EXIT_SUCCESS (0) by the command). On failure (including non-zero exit status), prints an explanation and exits; it does not return.

Functions

Detailed Description

Function Documentation