NAME
explain_strtoull - explain strtoull(3) errors
SYNOPSIS
#include <libexplain/strtoull.h>
const char *explain_strtoull(const char *nptr, char **endptr, int
base);
const char *explain_errno_strtoull(int errnum, const char *nptr, char
**endptr, int base);
void explain_message_strtoull(char *message, int message_size, const
char *nptr, char **endptr, int base);
void explain_message_errno_strtoull(char *message, int message_size,
int errnum, const char *nptr, char **endptr, int base);
DESCRIPTION
These functions may be used to obtain explanations for errors returned
by the strtoull(3) system call.
explain_strtoull
const char *explain_strtoull(const char *nptr, char **endptr, int
base);
The explain_strtoull function is used to obtain an explanation of an
error returned by the strtoull(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 strtoull(3) system
call.
endptr The original endptr, exactly as passed to the strtoull(3)
system call.
base The original base, exactly as passed to the strtoull(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:
unsigned long long result = strtoull(nptr, endptr, base);
if (result < 0)
{
fprintf(stderr, "%s\n", explain_strtoull(nptr, endptr,
base));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_strtoull_or_die(3) function.
explain_errno_strtoull
const char *explain_errno_strtoull(int errnum, const char *nptr, char
**endptr, int base);
The explain_errno_strtoull function is used to obtain an explanation of
an error returned by the strtoull(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 strtoull(3) system
call.
endptr The original endptr, exactly as passed to the strtoull(3)
system call.
base The original base, exactly as passed to the strtoull(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:
unsigned long long result = strtoull(nptr, endptr, base);
if (result < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_strtoull(err, nptr,
endptr, base));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_strtoull_or_die(3) function.
explain_message_strtoull
void explain_message_strtoull(char *message, int message_size, const
char *nptr, char **endptr, int base);
The explain_message_strtoull function is used to obtain an explanation
of an error returned by the strtoull(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 strtoull(3) system
call.
endptr The original endptr, exactly as passed to the strtoull(3)
system call.
base The original base, exactly as passed to the strtoull(3) system
call.
Example: This function is intended to be used in a fashion similar to
the following example:
unsigned long long result = strtoull(nptr, endptr, base);
if (result < 0)
{
char message[3000];
explain_message_strtoull(message, sizeof(message), nptr,
endptr, base);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_strtoull_or_die(3) function.
explain_message_errno_strtoull
void explain_message_errno_strtoull(char *message, int message_size,
int errnum, const char *nptr, char **endptr, int base);
The explain_message_errno_strtoull function is used to obtain an
explanation of an error returned by the strtoull(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 strtoull(3) system
call.
endptr The original endptr, exactly as passed to the strtoull(3)
system call.
base The original base, exactly as passed to the strtoull(3) system
call.
Example: This function is intended to be used in a fashion similar to
the following example:
unsigned long long result = strtoull(nptr, endptr, base);
if (result < 0)
{
int err = errno;
char message[3000];
explain_message_errno_strtoull(message, sizeof(message),
err, nptr, endptr, base);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_strtoull_or_die(3) function.
SEE ALSO
strtoull(3)
convert a string to an unsigned long integer
explain_strtoull_or_die(3)
convert a string to an unsigned long integer and report errors
COPYRIGHT
libexplain version 0.19
Copyright (C) 2009 Peter Miller
explain_strtoull(3)