lib-src/yow.c

   1 /*
   2  * yow.c
   3  *
   4  * Print a quotation from Zippy the Pinhead.
   5  * Qux <Kaufman-David@Yale> March 6, 1986
   6  *
   7  * This file is in the public domain because the author published it
   8  * with no copyright notice before the US signed the Bern Convention.
   9  *
  10  * With dynamic memory allocation.
  11  */
  12
  13 #ifdef HAVE_CONFIG_H
  14 #include <config.h>
  15 #endif
  16
  17 #include <stdio.h>
  18 #include <ctype.h>
  19 #ifdef HAVE_STRING_H
  20 #include <string.h>
  21 #endif
  22 #ifdef TIME_WITH_SYS_TIME
  23 #include <sys/time.h>
  24 #include <time.h>
  25 #else
  26 #ifdef HAVE_SYS_TIME_H
  27 #include <sys/time.h>
  28 #else
  29 #include <time.h>
  30 #endif
  31 #endif
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35 #include "epaths.h"             /* For PATH_DATA.  */
  36
  37 #define BUFSIZE  80
  38 #define SEP      '\0'
  39
  40 #ifndef YOW_FILE
  41 #define YOW_FILE "yow.lines"
  42 #endif
  43
  44 #ifdef MSDOS
  45 #define rootrelativepath(rel) \
  46 ({\
  47     static char res[BUFSIZE], *p;\
  48     strcpy (res, argv[0]);\
  49     p = res + strlen (res);\
  50     while (p != res && *p != '/' && *p != '\\' && *p != ':') p--;\
  51     strcpy (p + 1, "../");\
  52     strcpy (p + 4, rel);\
  53     &res;})
  54 #endif
  55
  56 #ifndef HAVE_STDLIB_H
  57 char *malloc __P ((size_t size))), *realloc __P ((POINTER_TYPE *ptr, size_t size));
  58 #endif
  59
  60 void yow();
  61 void setup_yow();
  62
  63 int
  64 main (argc, argv)
  65      int argc;
  66      char *argv[];
  67 {
  68   FILE *fp;
  69   char file[BUFSIZ];
  70
  71   if (argc > 2 && !strcmp (argv[1], "-f"))
  72     strcpy (file, argv[2]);
  73   else
  74 #ifdef vms
  75     sprintf (file, "%s%s", PATH_DATA, YOW_FILE);
  76 #else
  77     sprintf (file, "%s/%s", PATH_DATA, YOW_FILE);
  78 #endif
  79
  80   if ((fp = fopen(file, "r")) == NULL) {
  81     fprintf(stderr, "yow: ");
  82     perror(file);
  83     exit(1);
  84   }
  85
  86   /* initialize random seed */
  87   srand((int) (getpid() + time((time_t *) 0)));
  88
  89   setup_yow(fp);
  90   yow(fp);
  91   fclose(fp);
  92   return 0;
  93 }
  94
  95 static long len = -1;
  96 static long header_len;
  97
  98 #define AVG_LEN 40              /* average length of a quotation */
  99
 100 /* Sets len and header_len */
 101 void
 102 setup_yow(fp)
 103      FILE *fp;
 104 {
 105   int c;
 106
 107   /* Get length of file */
 108   /* Because the header (stuff before the first SEP) can be very long,
 109    * thus biasing our search in favor of the first quotation in the file,
 110    * we explicitly skip that. */
 111   while ((c = getc(fp)) != SEP) {
 112     if (c == EOF) {
 113       fprintf(stderr, "yow: file contains no separators\n");
 114       exit(2);
 115     }
 116   }
 117   header_len = ftell(fp);
 118   if (header_len > AVG_LEN)
 119     header_len -= AVG_LEN;      /* allow the first quotation to appear */
 120
 121   if (fseek(fp, 0L, 2) == -1) {
 122     perror("yow");
 123     exit(1);
 124   }
 125   len = ftell(fp) - header_len;
 126 }
 127
 128
 129 /* go to a random place in the file and print the quotation there */
 130 void
 131 yow (fp)
 132      FILE *fp;
 133 {
 134   long offset;
 135   int c, i = 0;
 136   char *buf;
 137   unsigned int bufsize;
 138
 139   offset = rand() % len + header_len;
 140   if (fseek(fp, offset, 0) == -1) {
 141     perror("yow");
 142     exit(1);
 143   }
 144
 145   /* Read until SEP, read next line, print it.
 146      (Note that we will never print anything before the first separator.)
 147      If we hit EOF looking for the first SEP, just recurse. */
 148   while ((c = getc(fp)) != SEP)
 149     if (c == EOF) {
 150       yow(fp);
 151       return;
 152     }
 153
 154   /* Skip leading whitespace, then read in a quotation.
 155      If we hit EOF before we find a non-whitespace char, recurse. */
 156   while (isspace(c = getc(fp)))
 157     ;
 158   if (c == EOF) {
 159     yow(fp);
 160     return;
 161   }
 162
 163   bufsize = BUFSIZE;
 164   buf = malloc(bufsize);
 165   if (buf == (char *)0) {
 166     fprintf(stderr, "yow: virtual memory exhausted\n");
 167     exit (3);
 168   }
 169
 170   buf[i++] = c;
 171   while ((c = getc(fp)) != SEP && c != EOF) {
 172     buf[i++] = c;
 173
 174     if (i == bufsize-1) {
 175       /* Yow! Is this quotation too long yet? */
 176       bufsize *= 2;
 177       buf = realloc(buf, bufsize);
 178       if (buf == (char *)0) {
 179         fprintf(stderr, "yow: virtual memory exhausted\n");
 180         exit (3);
 181       }
 182     }
 183   }
 184   buf[i++] = 0;
 185   printf("%s\n", buf);
 186 }
 187