glib/gprintf.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997, 2002  Peter Mattis, Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include "config.h"
  21
  22 #include <stdarg.h>
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25
  26 #include "gprintf.h"
  27 #include "gprintfint.h"
  28
  29
  30 /**
  31  * g_printf:
  32  * @format: a standard printf() format string, but notice
  33  *          <link linkend="string-precision">string precision pitfalls</link>.
  34  * @...: the arguments to insert in the output.
  35  *
  36  * An implementation of the standard printf() function which supports
  37  * positional parameters, as specified in the Single Unix Specification.
  38  *
  39  * As with the standard printf(), this does not automatically append a trailing
  40  * new-line character to the message, so typically @format should end with its
  41  * own new-line character.
  42  *
  43  * Returns: the number of bytes printed.
  44  *
  45  * Since: 2.2
  46  **/
  47 gint
  48 g_printf (gchar const *format,
  49           ...)
  50 {
  51   va_list args;
  52   gint retval;
  53
  54   va_start (args, format);
  55   retval = g_vprintf (format, args);
  56   va_end (args);
  57
  58   return retval;
  59 }
  60
  61 /**
  62  * g_fprintf:
  63  * @file: the stream to write to.
  64  * @format: a standard printf() format string, but notice
  65  *          <link linkend="string-precision">string precision pitfalls</link>.
  66  * @...: the arguments to insert in the output.
  67  *
  68  * An implementation of the standard fprintf() function which supports
  69  * positional parameters, as specified in the Single Unix Specification.
  70  *
  71  * Returns: the number of bytes printed.
  72  *
  73  * Since: 2.2
  74  **/
  75 gint
  76 g_fprintf (FILE        *file,
  77            gchar const *format,
  78            ...)
  79 {
  80   va_list args;
  81   gint retval;
  82
  83   va_start (args, format);
  84   retval = g_vfprintf (file, format, args);
  85   va_end (args);
  86
  87   return retval;
  88 }
  89
  90 /**
  91  * g_sprintf:
  92  * @string: A pointer to a memory buffer to contain the resulting string. It
  93  *          is up to the caller to ensure that the allocated buffer is large
  94  *          enough to hold the formatted result
  95  * @format: a standard printf() format string, but notice
  96  *          <link linkend="string-precision">string precision pitfalls</link>.
  97  * @...: the arguments to insert in the output.
  98  *
  99  * An implementation of the standard sprintf() function which supports
 100  * positional parameters, as specified in the Single Unix Specification.
 101  *
 102  * Note that it is usually better to use g_snprintf(), to avoid the
 103  * risk of buffer overflow.
 104  *
 105  * See also g_strdup_printf().
 106  *
 107  * Returns: the number of bytes printed.
 108  *
 109  * Since: 2.2
 110  **/
 111 gint
 112 g_sprintf (gchar       *string,
 113            gchar const *format,
 114            ...)
 115 {
 116   va_list args;
 117   gint retval;
 118
 119   va_start (args, format);
 120   retval = g_vsprintf (string, format, args);
 121   va_end (args);
 122
 123   return retval;
 124 }
 125
 126 /**
 127  * g_snprintf:
 128  * @string: the buffer to hold the output.
 129  * @n: the maximum number of bytes to produce (including the
 130  *     terminating nul character).
 131  * @format: a standard printf() format string, but notice
 132  *          <link linkend="string-precision">string precision pitfalls</link>.
 133  * @...: the arguments to insert in the output.
 134  *
 135  * A safer form of the standard sprintf() function. The output is guaranteed
 136  * to not exceed @n characters (including the terminating nul character), so
 137  * it is easy to ensure that a buffer overflow cannot occur.
 138  *
 139  * See also g_strdup_printf().
 140  *
 141  * In versions of GLib prior to 1.2.3, this function may return -1 if the
 142  * output was truncated, and the truncated string may not be nul-terminated.
 143  * In versions prior to 1.3.12, this function returns the length of the output
 144  * string.
 145  *
 146  * The return value of g_snprintf() conforms to the snprintf()
 147  * function as standardized in ISO C99. Note that this is different from
 148  * traditional snprintf(), which returns the length of the output string.
 149  *
 150  * The format string may contain positional parameters, as specified in
 151  * the Single Unix Specification.
 152  *
 153  * Returns: the number of bytes which would be produced if the buffer
 154  *     was large enough.
 155  **/
 156 gint
 157 g_snprintf (gchar       *string,
 158             gulong       n,
 159             gchar const *format,
 160             ...)
 161 {
 162   va_list args;
 163   gint retval;
 164
 165   va_start (args, format);
 166   retval = g_vsnprintf (string, n, format, args);
 167   va_end (args);
 168
 169   return retval;
 170 }
 171
 172 /**
 173  * g_vprintf:
 174  * @format: a standard printf() format string, but notice
 175  *          <link linkend="string-precision">string precision pitfalls</link>.
 176  * @args: the list of arguments to insert in the output.
 177  *
 178  * An implementation of the standard vprintf() function which supports
 179  * positional parameters, as specified in the Single Unix Specification.
 180  *
 181  * Returns: the number of bytes printed.
 182  *
 183  * Since: 2.2
 184  **/
 185 gint
 186 g_vprintf (gchar const *format,
 187            va_list      args)
 188 {
 189   g_return_val_if_fail (format != NULL, -1);
 190
 191   return _g_vprintf (format, args);
 192 }
 193
 194 /**
 195  * g_vfprintf:
 196  * @file: the stream to write to.
 197  * @format: a standard printf() format string, but notice
 198  *          <link linkend="string-precision">string precision pitfalls</link>.
 199  * @args: the list of arguments to insert in the output.
 200  *
 201  * An implementation of the standard fprintf() function which supports
 202  * positional parameters, as specified in the Single Unix Specification.
 203  *
 204  * Returns: the number of bytes printed.
 205  *
 206  * Since: 2.2
 207  **/
 208 gint
 209 g_vfprintf (FILE        *file,
 210             gchar const *format,
 211             va_list      args)
 212 {
 213   g_return_val_if_fail (format != NULL, -1);
 214
 215   return _g_vfprintf (file, format, args);
 216 }
 217
 218 /**
 219  * g_vsprintf:
 220  * @string: the buffer to hold the output.
 221  * @format: a standard printf() format string, but notice
 222  *          <link linkend="string-precision">string precision pitfalls</link>.
 223  * @args: the list of arguments to insert in the output.
 224  *
 225  * An implementation of the standard vsprintf() function which supports
 226  * positional parameters, as specified in the Single Unix Specification.
 227  *
 228  * Returns: the number of bytes printed.
 229  *
 230  * Since: 2.2
 231  **/
 232 gint
 233 g_vsprintf (gchar        *string,
 234             gchar const *format,
 235             va_list      args)
 236 {
 237   g_return_val_if_fail (string != NULL, -1);
 238   g_return_val_if_fail (format != NULL, -1);
 239
 240   return _g_vsprintf (string, format, args);
 241 }
 242
 243 /**
 244  * g_vsnprintf:
 245  * @string: the buffer to hold the output.
 246  * @n: the maximum number of bytes to produce (including the
 247  *     terminating nul character).
 248  * @format: a standard printf() format string, but notice
 249  *          <link linkend="string-precision">string precision pitfalls</link>.
 250  * @args: the list of arguments to insert in the output.
 251  *
 252  * A safer form of the standard vsprintf() function. The output is guaranteed
 253  * to not exceed @n characters (including the terminating nul character), so
 254  * it is easy to ensure that a buffer overflow cannot occur.
 255  *
 256  * See also g_strdup_vprintf().
 257  *
 258  * In versions of GLib prior to 1.2.3, this function may return -1 if the
 259  * output was truncated, and the truncated string may not be nul-terminated.
 260  * In versions prior to 1.3.12, this function returns the length of the output
 261  * string.
 262  *
 263  * The return value of g_vsnprintf() conforms to the vsnprintf() function
 264  * as standardized in ISO C99. Note that this is different from traditional
 265  * vsnprintf(), which returns the length of the output string.
 266  *
 267  * The format string may contain positional parameters, as specified in
 268  * the Single Unix Specification.
 269  *
 270  * Returns: the number of bytes which would be produced if the buffer
 271  *  was large enough.
 272  */
 273 gint
 274 g_vsnprintf (gchar       *string,
 275              gulong       n,
 276              gchar const *format,
 277              va_list      args)
 278 {
 279   g_return_val_if_fail (n == 0 || string != NULL, -1);
 280   g_return_val_if_fail (format != NULL, -1);
 281
 282   return _g_vsnprintf (string, n, format, args);
 283 }
 284
 285 /**
 286  * g_vasprintf:
 287  * @string: the return location for the newly-allocated string.
 288  * @format: a standard printf() format string, but notice
 289  *          <link linkend="string-precision">string precision pitfalls</link>.
 290  * @args: the list of arguments to insert in the output.
 291  *
 292  * An implementation of the GNU vasprintf() function which supports
 293  * positional parameters, as specified in the Single Unix Specification.
 294  * This function is similar to g_vsprintf(), except that it allocates a
 295  * string to hold the output, instead of putting the output in a buffer
 296  * you allocate in advance.
 297  *
 298  * Returns: the number of bytes printed.
 299  *
 300  * Since: 2.4
 301  **/
 302 gint
 303 g_vasprintf (gchar      **string,
 304              gchar const *format,
 305              va_list      args)
 306 {
 307   gint len;
 308   g_return_val_if_fail (string != NULL, -1);
 309
 310 #if !defined(HAVE_GOOD_PRINTF)
 311
 312   len = _g_gnulib_vasprintf (string, format, args);
 313   if (len < 0)
 314     *string = NULL;
 315
 316 #elif defined (HAVE_VASPRINTF)
 317
 318   len = vasprintf (string, format, args);
 319   if (len < 0)
 320     *string = NULL;
 321   else if (!g_mem_is_system_malloc ())
 322     {
 323       /* vasprintf returns malloc-allocated memory */
 324       gchar *string1 = g_strndup (*string, len);
 325       free (*string);
 326       *string = string1;
 327     }
 328
 329 #else
 330
 331   {
 332     va_list args2;
 333
 334     G_VA_COPY (args2, args);
 335
 336     *string = g_new (gchar, g_printf_string_upper_bound (format, args));
 337
 338     len = _g_vsprintf (*string, format, args2);
 339     va_end (args2);
 340   }
 341 #endif
 342
 343   return len;
 344 }