glib2.0/glib/gprintf.c

373 lines
10 KiB
C

/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997, 2002 Peter Mattis, Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include "gprintf.h"
#include "gprintfint.h"
/**
* g_printf:
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @...: the arguments to insert in the output.
*
* An implementation of the standard printf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* As with the standard printf(), this does not automatically append a trailing
* new-line character to the message, so typically @format should end with its
* own new-line character.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_printf (gchar const *format,
...)
{
va_list args;
gint retval;
va_start (args, format);
retval = g_vprintf (format, args);
va_end (args);
return retval;
}
/**
* g_fprintf:
* @file: (not nullable): the stream to write to.
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @...: the arguments to insert in the output.
*
* An implementation of the standard fprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_fprintf (FILE *file,
gchar const *format,
...)
{
va_list args;
gint retval;
va_start (args, format);
retval = g_vfprintf (file, format, args);
va_end (args);
return retval;
}
/**
* g_sprintf:
* @string: A pointer to a memory buffer to contain the resulting string. It
* is up to the caller to ensure that the allocated buffer is large
* enough to hold the formatted result
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @...: the arguments to insert in the output.
*
* An implementation of the standard sprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* Note that it is usually better to use g_snprintf(), to avoid the
* risk of buffer overflow.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* See also g_strdup_printf().
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_sprintf (gchar *string,
gchar const *format,
...)
{
va_list args;
gint retval;
va_start (args, format);
retval = g_vsprintf (string, format, args);
va_end (args);
return retval;
}
/**
* g_snprintf:
* @string: the buffer to hold the output.
* @n: the maximum number of bytes to produce (including the
* terminating nul character).
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @...: the arguments to insert in the output.
*
* A safer form of the standard sprintf() function. The output is guaranteed
* to not exceed @n characters (including the terminating nul character), so
* it is easy to ensure that a buffer overflow cannot occur.
*
* See also g_strdup_printf().
*
* In versions of GLib prior to 1.2.3, this function may return -1 if the
* output was truncated, and the truncated string may not be nul-terminated.
* In versions prior to 1.3.12, this function returns the length of the output
* string.
*
* The return value of g_snprintf() conforms to the snprintf()
* function as standardized in ISO C99. Note that this is different from
* traditional snprintf(), which returns the length of the output string.
*
* The format string may contain positional parameters, as specified in
* the Single Unix Specification.
*
* Returns: the number of bytes which would be produced if the buffer
* was large enough.
**/
gint
g_snprintf (gchar *string,
gulong n,
gchar const *format,
...)
{
va_list args;
gint retval;
va_start (args, format);
retval = g_vsnprintf (string, n, format, args);
va_end (args);
return retval;
}
/**
* g_vprintf:
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @args: the list of arguments to insert in the output.
*
* An implementation of the standard vprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_vprintf (gchar const *format,
va_list args)
{
g_return_val_if_fail (format != NULL, -1);
return _g_vprintf (format, args);
}
/**
* g_vfprintf:
* @file: (not nullable): the stream to write to.
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @args: the list of arguments to insert in the output.
*
* An implementation of the standard fprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_vfprintf (FILE *file,
gchar const *format,
va_list args)
{
g_return_val_if_fail (format != NULL, -1);
return _g_vfprintf (file, format, args);
}
/**
* g_vsprintf:
* @string: the buffer to hold the output.
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @args: the list of arguments to insert in the output.
*
* An implementation of the standard vsprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed.
*
* Since: 2.2
**/
gint
g_vsprintf (gchar *string,
gchar const *format,
va_list args)
{
g_return_val_if_fail (string != NULL, -1);
g_return_val_if_fail (format != NULL, -1);
return _g_vsprintf (string, format, args);
}
/**
* g_vsnprintf:
* @string: the buffer to hold the output.
* @n: the maximum number of bytes to produce (including the
* terminating nul character).
* @format: a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @args: the list of arguments to insert in the output.
*
* A safer form of the standard vsprintf() function. The output is guaranteed
* to not exceed @n characters (including the terminating nul character), so
* it is easy to ensure that a buffer overflow cannot occur.
*
* See also g_strdup_vprintf().
*
* In versions of GLib prior to 1.2.3, this function may return -1 if the
* output was truncated, and the truncated string may not be nul-terminated.
* In versions prior to 1.3.12, this function returns the length of the output
* string.
*
* The return value of g_vsnprintf() conforms to the vsnprintf() function
* as standardized in ISO C99. Note that this is different from traditional
* vsnprintf(), which returns the length of the output string.
*
* The format string may contain positional parameters, as specified in
* the Single Unix Specification.
*
* Returns: the number of bytes which would be produced if the buffer
* was large enough.
*/
gint
g_vsnprintf (gchar *string,
gulong n,
gchar const *format,
va_list args)
{
g_return_val_if_fail (n == 0 || string != NULL, -1);
g_return_val_if_fail (format != NULL, -1);
return _g_vsnprintf (string, n, format, args);
}
/**
* g_vasprintf:
* @string: (not optional) (nullable): the return location for the newly-allocated string,
* which will be %NULL if (and only if) this function fails
* @format: (not nullable): a standard printf() format string, but notice
* [string precision pitfalls][string-precision]
* @args: the list of arguments to insert in the output.
*
* An implementation of the GNU vasprintf() function which supports
* positional parameters, as specified in the Single Unix Specification.
* This function is similar to g_vsprintf(), except that it allocates a
* string to hold the output, instead of putting the output in a buffer
* you allocate in advance.
*
* The returned value in @string is guaranteed to be non-NULL, unless
* @format contains `%lc` or `%ls` conversions, which can fail if no
* multibyte representation is available for the given character.
*
* `glib/gprintf.h` must be explicitly included in order to use this function.
*
* Returns: the number of bytes printed, or `-1` on failure
*
* Since: 2.4
**/
gint
g_vasprintf (gchar **string,
gchar const *format,
va_list args)
{
gint len;
g_return_val_if_fail (string != NULL, -1);
#if !defined(USE_SYSTEM_PRINTF)
len = _g_gnulib_vasprintf (string, format, args);
if (len < 0)
*string = NULL;
#elif defined (HAVE_VASPRINTF)
{
int saved_errno;
len = vasprintf (string, format, args);
saved_errno = errno;
if (len < 0)
{
if (saved_errno == ENOMEM)
g_error ("%s: failed to allocate memory", G_STRLOC);
else
*string = NULL;
}
}
#else
{
va_list args2;
G_VA_COPY (args2, args);
*string = g_new (gchar, g_printf_string_upper_bound (format, args));
len = _g_vsprintf (*string, format, args2);
va_end (args2);
if (len < 0)
{
g_free (*string);
*string = NULL;
}
}
#endif
return len;
}