pd.if.org Git - pdclib/blob - functions/stdio/fgets.c

   1 /* ----------------------------------------------------------------------------
   2  * $Id$
   3  * ----------------------------------------------------------------------------
   4  * Public Domain C Library - http://pdclib.sourceforge.net
   5  * This code is Public Domain. Use, modify, and redistribute at will.
   6  * --------------------------------------------------------------------------*/
   7
   8 char * fgets( char * restrict s, int n, FILE * restrict stream ) { /* TODO */ };
   9
  10 /* PDPC code - unreviewed
  11 /*
  12
  13 In fgets, we have the following possibilites...
  14
  15 1. we found a genuine '\n' that terminated the search.
  16 2. we hit the '\n' at the endbuf.
  17 3. we hit the '\n' sentinel.
  18
  19 */
  20 #ifndef __MVS__
  21 char *fgets(char *s, int n, FILE *stream)
  22 {
  23     char *p;
  24     register char *t;
  25     register char *u = s;
  26     int c;
  27     int processed;
  28 #ifdef __OS2__
  29     ULONG actualRead;
  30     APIRET rc;
  31 #endif
  32 #ifdef __MSDOS__
  33     size_t actualRead;
  34     int errind;
  35 #endif
  36
  37     if (stream->quickText)
  38     {
  39         p = stream->upto + n - 1;
  40         t = stream->upto;
  41         if (p < stream->endbuf)
  42         {
  43             c = *p;
  44             *p = '\n';
  45 #ifdef __OS2__
  46             if (n < 8)
  47             {
  48 #endif
  49                 while ((*u++ = *t++) != '\n') ; /* tight inner loop */
  50 #ifdef __OS2__
  51             }
  52             else
  53             {
  54                 register unsigned int *i1;
  55                 register unsigned int *i2;
  56                 register unsigned int z;
  57
  58                 i1 = (unsigned int *)t;
  59                 i2 = (unsigned int *)u;
  60                 while (1)
  61                 {
  62                     z = *i1;
  63                     if ((z & 0xffU) == '\n') break;
  64                     z >>= 8;
  65                     if ((z & 0xffU) == '\n') break;
  66                     z >>= 8;
  67                     if ((z & 0xffU) == '\n') break;
  68                     z >>= 8;
  69                     if ((z & 0xffU) == '\n') break;
  70                     *i2++ = *i1++;
  71                 }
  72                 t = (char *)i1;
  73                 u = (char *)i2;
  74                 while ((*u++ = *t++) != '\n') ;
  75             }
  76 #endif
  77             *p = (char)c;
  78             if (t <= p)
  79             {
  80                 if (*(t - 2) == '\r') /* t is protected, u isn't */
  81                 {
  82                     *(u - 2) = '\n';
  83                     *(u - 1) = '\0';
  84                 }
  85                 else
  86                 {
  87                     *u = '\0';
  88                 }
  89                 stream->upto = t;
  90                 return (s);
  91             }
  92             else
  93             {
  94                 processed = (int)(t - stream->upto) - 1;
  95                 stream->upto = t - 1;
  96                 u--;
  97             }
  98         }
  99         else
 100         {
 101             while ((*u++ = *t++) != '\n') ; /* tight inner loop */
 102             if (t <= stream->endbuf)
 103             {
 104                 if (*(t - 2) == '\r') /* t is protected, u isn't */
 105                 {
 106                     *(u - 2) = '\n';
 107                     *(u - 1) = '\0';
 108                 }
 109                 else
 110                 {
 111                     *u = '\0';
 112                 }
 113                 stream->upto = t;
 114                 return (s);
 115             }
 116             else
 117             {
 118                 processed = (int)(t - stream->upto) - 1;
 119                 stream->upto = t - 1;
 120                 u--;
 121             }
 122         }
 123     }
 124     else
 125     {
 126         processed = 0;
 127     }
 128
 129     if (n < 1)
 130     {
 131         return (NULL);
 132     }
 133     if (n < 2)
 134     {
 135         *u = '\0';
 136         return (s);
 137     }
 138     if (stream->ungetCh != -1)
 139     {
 140         processed++;
 141         *u++ = (char)stream->ungetCh;
 142         stream->ungetCh = -1;
 143     }
 144     while (1)
 145     {
 146         t = stream->upto;
 147         p = stream->upto + (n - processed) - 1;
 148         if (p < stream->endbuf)
 149         {
 150             c = *p;
 151             *p = '\n';
 152         }
 153         if (stream->noNl)
 154         {
 155             while (((*u++ = *t) != '\n') && (*t++ != '\r')) ;
 156             if (*(u - 1) == '\n')
 157             {
 158                 t++;
 159             }
 160             else
 161             {
 162                 u--;
 163                 while ((*u++ = *t++) != '\n') ;
 164             }
 165         }
 166         else
 167         {
 168             while ((*u++ = *t++) != '\n') ; /* tight inner loop */
 169         }
 170         if (p < stream->endbuf)
 171         {
 172             *p = (char)c;
 173         }
 174         if (((t <= p) && (p < stream->endbuf))
 175            || ((t <= stream->endbuf) && (p >= stream->endbuf)))
 176         {
 177             if (stream->textMode)
 178             {
 179                 if (stream->noNl)
 180                 {
 181                     if ((*(t - 1) == '\r') || (*(t - 1) == '\n'))
 182                     {
 183                         *(u - 1) = '\0';
 184                     }
 185                     else
 186                     {
 187                         *u = '\0';
 188                     }
 189                 }
 190                 else if (*(t - 2) == '\r') /* t is protected, u isn't */
 191                 {
 192                     *(u - 2) = '\n';
 193                     *(u - 1) = '\0';
 194                 }
 195                 else
 196                 {
 197                     *u = '\0';
 198                 }
 199             }
 200             stream->upto = t;
 201             if (stream->textMode)
 202             {
 203                 stream->quickText = 1;
 204             }
 205             return (s);
 206         }
 207         else if (((t > p) && (p < stream->endbuf))
 208                  || ((t > stream->endbuf) && (p >= stream->endbuf)))
 209         {
 210             int leave = 1;
 211
 212             if (stream->textMode)
 213             {
 214                 if (t > stream->endbuf)
 215                 {
 216                     if ((t - stream->upto) > 1)
 217                     {
 218                         if (*(t - 2) == '\r') /* t is protected, u isn't */
 219                         {
 220                             processed -= 1; /* preparation for add */
 221                         }
 222                     }
 223                     leave = 0;
 224                 }
 225                 else
 226                 {
 227                     if ((*(t - 2) == '\r') && (*(t - 1) == '\n'))
 228                     {
 229                         *(u - 2) = '\n';
 230                         *(u - 1) = '\0';
 231                     }
 232                     else
 233                     {
 234                         t--;
 235                         *(u - 1) = '\0';
 236                     }
 237                 }
 238             }
 239             else if (t > stream->endbuf)
 240             {
 241                 leave = 0;
 242             }
 243             else
 244             {
 245                 *u = '\0';
 246             }
 247             if (leave)
 248             {
 249                 stream->upto = t;
 250                 if (stream->textMode)
 251                 {
 252                     stream->quickText = 1;
 253                 }
 254                 return (s);
 255             }
 256         }
 257         processed += (int)(t - stream->upto) - 1;
 258         u--;
 259         stream->bufStartR += (stream->endbuf - stream->fbuf);
 260 #ifdef __OS2__
 261         rc = DosRead(stream->hfile, stream->fbuf, stream->szfbuf, &actualRead);
 262         if (rc != 0)
 263         {
 264             actualRead = 0;
 265             stream->errorInd = 1;
 266             errno = rc;
 267         }
 268 #endif
 269 #ifdef __MSDOS__
 270         actualRead = __read(stream->hfile,
 271                             stream->fbuf,
 272                             stream->szfbuf,
 273                             &errind);
 274         if (errind)
 275         {
 276             errno = actualRead;
 277             actualRead = 0;
 278             stream->errorInd = 1;
 279         }
 280 #endif
 281         stream->endbuf = stream->fbuf + actualRead;
 282         *stream->endbuf = '\n';
 283         if (actualRead == 0)
 284         {
 285             *u = '\0';
 286             if ((u - s) <= 1)
 287             {
 288                 stream->eofInd = 1;
 289                 return (NULL);
 290             }
 291             else
 292             {
 293                 return (s);
 294             }
 295         }
 296         stream->upto = stream->fbuf;
 297     }
 298 }
 299 #endif
 300 */