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