src/afsweb/apache_includes/1.3.1/ap.h

   1 /* ====================================================================
   2  * Copyright (c) 1998 The Apache Group.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the Apache Group
  19  *    for use in the Apache HTTP server project (http://www.apache.org/)."
  20  *
  21  * 4. The names "Apache Server" and "Apache Group" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    apache@apache.org.
  25  *
  26  * 5. Products derived from this software may not be called "Apache"
  27  *    nor may "Apache" appear in their names without prior written
  28  *    permission of the Apache Group.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the Apache Group
  33  *    for use in the Apache HTTP server project (http://www.apache.org/)."
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  *
  49  * This software consists of voluntary contributions made by many
  50  * individuals on behalf of the Apache Group and was originally based
  51  * on public domain software written at the National Center for
  52  * Supercomputing Applications, University of Illinois, Urbana-Champaign.
  53  * For more information on the Apache Group and the Apache HTTP server
  54  * project, please see <http://www.apache.org/>.
  55  *
  56  * The ap_vsnprintf/ap_snprintf functions are based on, and used with the
  57  * permission of, the  SIO stdio-replacement strx_* functions by Panos
  58  * Tsirigotis <panos@alumni.cs.colorado.edu> for xinetd.
  59  */
  60
  61 #ifndef APACHE_AP_H
  62 #define APACHE_AP_H
  63
  64 #ifdef __cplusplus
  65 extern "C" {
  66 #endif
  67
  68     API_EXPORT(char *) ap_cpystrn(char *, const char *, size_t);
  69     int ap_slack(int, int);
  70       API_EXPORT(int) ap_snprintf(char *, size_t, const char *, ...);
  71       API_EXPORT(int) ap_vsnprintf(char *, size_t, const char *, va_list ap);
  72     int ap_execle(const char *, const char *, ...);
  73     int ap_execve(const char *, const char *argv[], const char *envp[]);
  74
  75 /* small utility macros to make things easier to read */
  76
  77 #ifdef WIN32
  78 #define ap_killpg(x, y)
  79 #else
  80 #ifdef NO_KILLPG
  81 #define ap_killpg(x, y)         (kill (-(x), (y)))
  82 #else
  83 #define ap_killpg(x, y)         (killpg ((x), (y)))
  84 #endif
  85 #endif                          /* WIN32 */
  86
  87 /* ap_vformatter() is a generic printf-style formatting routine
  88  * with some extensions.  The extensions are:
  89  *
  90  * %pA  takes a struct in_addr *, and prints it as a.b.c.d
  91  * %pI  takes a struct sockaddr_in * and prints it as a.b.c.d:port
  92  * %pp  takes a void * and outputs it in hex
  93  *
  94  * The %p hacks are to force gcc's printf warning code to skip
  95  * over a pointer argument without complaining.  This does
  96  * mean that the ANSI-style %p (output a void * in hex format) won't
  97  * work as expected at all, but that seems to be a fair trade-off
  98  * for the increased robustness of having printf-warnings work.
  99  *
 100  * Additionally, ap_vformatter allows for arbitrary output methods
 101  * using the ap_vformatter_buff and flush_func.
 102  *
 103  * The ap_vformatter_buff has two elements curpos and endpos.
 104  * curpos is where ap_vformatter will write the next byte of output.
 105  * It proceeds writing output to curpos, and updating curpos, until
 106  * either the end of output is reached, or curpos == endpos (i.e. the
 107  * buffer is full).
 108  *
 109  * If the end of output is reached, ap_vformatter returns the
 110  * number of bytes written.
 111  *
 112  * When the buffer is full, the flush_func is called.  The flush_func
 113  * can return -1 to indicate that no further output should be attempted,
 114  * and ap_vformatter will return immediately with -1.  Otherwise
 115  * the flush_func should flush the buffer in whatever manner is
 116  * appropriate, re-initialize curpos and endpos, and return 0.
 117  *
 118  * Note that flush_func is only invoked as a result of attempting to
 119  * write another byte at curpos when curpos >= endpos.  So for
 120  * example, it's possible when the output exactly matches the buffer
 121  * space available that curpos == endpos will be true when
 122  * ap_vformatter returns.
 123  *
 124  * ap_vformatter does not call out to any other code, it is entirely
 125  * self-contained.  This allows the callers to do things which are
 126  * otherwise "unsafe".  For example, ap_psprintf uses the "scratch"
 127  * space at the unallocated end of a block, and doesn't actually
 128  * complete the allocation until ap_vformatter returns.  ap_psprintf
 129  * would be completely broken if ap_vformatter were to call anything
 130  * that used a pool.  Similarly http_bprintf() uses the "scratch"
 131  * space at the end of its output buffer, and doesn't actually note
 132  * that the space is in use until it either has to flush the buffer
 133  * or until ap_vformatter returns.
 134  */
 135
 136     typedef struct {
 137         char *curpos;
 138         char *endpos;
 139     } ap_vformatter_buff;
 140
 141       API_EXPORT(int) ap_vformatter(int (*flush_func) (ap_vformatter_buff *),
 142                                     ap_vformatter_buff *, const char *fmt,
 143                                     va_list ap);
 144
 145 /* These are snprintf implementations based on ap_vformatter().
 146  *
 147  * Note that various standards and implementations disagree on the return
 148  * value of snprintf, and side-effects due to %n in the formatting string.
 149  * ap_snprintf behaves as follows:
 150  *
 151  * Process the format string until the entire string is exhausted, or
 152  * the buffer fills.  If the buffer fills then stop processing immediately
 153  * (so no further %n arguments are processed), and return the buffer
 154  * length.  In all cases the buffer is NUL terminated.
 155  *
 156  * In no event does ap_snprintf return a negative number.  It's not possible
 157  * to distinguish between an output which was truncated, and an output which
 158  * exactly filled the buffer.
 159  */
 160       API_EXPORT(int) ap_snprintf(char *buf, size_t len, const char *format,
 161                                   ...)
 162         __attribute__ ((format(printf, 3, 4)));
 163       API_EXPORT(int) ap_vsnprintf(char *buf, size_t len, const char *format,
 164                                    va_list ap);
 165
 166 #ifdef __cplusplus
 167 }
 168 #endif
 169 #endif                          /* !APACHE_AP_H */