html.c

   1 /* html.c: helper functions for html output
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include <unistd.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <stdarg.h>
  13 #include <string.h>
  14
  15 int htmlfd = STDOUT_FILENO;
  16
  17 char *fmt(const char *format, ...)
  18 {
  19         static char buf[8][1024];
  20         static int bufidx;
  21         int len;
  22         va_list args;
  23
  24         bufidx++;
  25         bufidx &= 7;
  26
  27         va_start(args, format);
  28         len = vsnprintf(buf[bufidx], sizeof(buf[bufidx]), format, args);
  29         va_end(args);
  30         if (len>sizeof(buf[bufidx])) {
  31                 fprintf(stderr, "[html.c] string truncated: %s\n", format);
  32                 exit(1);
  33         }
  34         return buf[bufidx];
  35 }
  36
  37 void html(const char *txt)
  38 {
  39         write(htmlfd, txt, strlen(txt));
  40 }
  41
  42 void htmlf(const char *format, ...)
  43 {
  44         static char buf[65536];
  45         va_list args;
  46
  47         va_start(args, format);
  48         vsnprintf(buf, sizeof(buf), format, args);
  49         va_end(args);
  50         html(buf);
  51 }
  52
  53 void html_txt(char *txt)
  54 {
  55         char *t = txt;
  56         while(t && *t){
  57                 int c = *t;
  58                 if (c=='<' || c=='>' || c=='&') {
  59                         write(htmlfd, txt, t - txt);
  60                         if (c=='>')
  61                                 html("&gt;");
  62                         else if (c=='<')
  63                                 html("&lt;");
  64                         else if (c=='&')
  65                                 html("&amp;");
  66                         txt = t+1;
  67                 }
  68                 t++;
  69         }
  70         if (t!=txt)
  71                 html(txt);
  72 }
  73
  74 void html_ntxt(int len, char *txt)
  75 {
  76         char *t = txt;
  77         while(t && *t && len--){
  78                 int c = *t;
  79                 if (c=='<' || c=='>' || c=='&') {
  80                         write(htmlfd, txt, t - txt);
  81                         if (c=='>')
  82                                 html("&gt;");
  83                         else if (c=='<')
  84                                 html("&lt;");
  85                         else if (c=='&')
  86                                 html("&amp;");
  87                         txt = t+1;
  88                 }
  89                 t++;
  90         }
  91         if (t!=txt)
  92                 write(htmlfd, txt, t - txt);
  93         if (len<0)
  94                 html("...");
  95 }
  96
  97 void html_attr(char *txt)
  98 {
  99         char *t = txt;
 100         while(t && *t){
 101                 int c = *t;
 102                 if (c=='<' || c=='>' || c=='\'') {
 103                         write(htmlfd, txt, t - txt);
 104                         if (c=='>')
 105                                 html("&gt;");
 106                         else if (c=='<')
 107                                 html("&lt;");
 108                         else if (c=='\'')
 109                                 html("&quote;");
 110                         txt = t+1;
 111                 }
 112                 t++;
 113         }
 114         if (t!=txt)
 115                 html(txt);
 116 }
 117
 118 void html_hidden(char *name, char *value)
 119 {
 120         html("<input type='hidden' name='");
 121         html_attr(name);
 122         html("' value='");
 123         html_attr(value);
 124         html("'/>");
 125 }
 126
 127 void html_option(char *value, char *text, char *selected_value)
 128 {
 129         html("<option value='");
 130         html_attr(value);
 131         html("'");
 132         if (selected_value && !strcmp(selected_value, value))
 133                 html(" selected='selected'");
 134         html(">");
 135         html_txt(text);
 136         html("</option>\n");
 137 }
 138
 139 void html_link_open(char *url, char *title, char *class)
 140 {
 141         html("<a href='");
 142         html_attr(url);
 143         if (title) {
 144                 html("' title='");
 145                 html_attr(title);
 146         }
 147         if (class) {
 148                 html("' class='");
 149                 html_attr(class);
 150         }
 151         html("'>");
 152 }
 153
 154 void html_link_close(void)
 155 {
 156         html("</a>");
 157 }
 158
 159 void html_fileperm(unsigned short mode)
 160 {
 161         htmlf("%c%c%c", (mode & 4 ? 'r' : '-'),
 162               (mode & 2 ? 'w' : '-'), (mode & 1 ? 'x' : '-'));
 163 }
 164
 165 int html_include(const char *filename)
 166 {
 167         FILE *f;
 168         char buf[4096];
 169         size_t len;
 170
 171         if (!(f = fopen(filename, "r")))
 172                 return -1;
 173         while((len = fread(buf, 1, 4096, f)) > 0)
 174                 write(htmlfd, buf, len);
 175         fclose(f);
 176         return 0;
 177 }
 178
 179 int hextoint(char c)
 180 {
 181         if (c >= 'a' && c <= 'f')
 182                 return 10 + c - 'a';
 183         else if (c >= 'A' && c <= 'F')
 184                 return 10 + c - 'A';
 185         else if (c >= '0' && c <= '9')
 186                 return c - '0';
 187         else
 188                 return -1;
 189 }
 190
 191 char *convert_query_hexchar(char *txt)
 192 {
 193         int d1, d2;
 194         if (strlen(txt) < 3) {
 195                 *txt = '\0';
 196                 return txt-1;
 197         }
 198         d1 = hextoint(*(txt+1));
 199         d2 = hextoint(*(txt+2));
 200         if (d1<0 || d2<0) {
 201                 strcpy(txt, txt+3);
 202                 return txt-1;
 203         } else {
 204                 *txt = d1 * 16 + d2;
 205                 strcpy(txt+1, txt+3);
 206                 return txt;
 207         }
 208 }
 209
 210 int http_parse_querystring(char *txt, void (*fn)(const char *name, const char *value))
 211 {
 212         char *t, *value = NULL, c;
 213
 214         if (!txt)
 215                 return 0;
 216
 217         t = txt = strdup(txt);
 218         if (t == NULL) {
 219                 printf("Out of memory\n");
 220                 exit(1);
 221         }
 222         while((c=*t) != '\0') {
 223                 if (c=='=') {
 224                         *t = '\0';
 225                         value = t+1;
 226                 } else if (c=='+') {
 227                         *t = ' ';
 228                 } else if (c=='%') {
 229                         t = convert_query_hexchar(t);
 230                 } else if (c=='&') {
 231                         *t = '\0';
 232                         (*fn)(txt, value);
 233                         txt = t+1;
 234                         value = NULL;
 235                 }
 236                 t++;
 237         }
 238         if (t!=txt)
 239                 (*fn)(txt, value);
 240         return 0;
 241 }