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 void yow();
  54 void setup_yow();
  55
  56 int
  57 main (argc, argv)
  58      int argc;
  59      char *argv[];
  60 {
  61   FILE *fp;
  62   char file[BUFSIZ];
  63
  64   if (argc > 2 && !strcmp (argv[1], "-f"))
  65     strcpy (file, argv[2]);
  66   else
  67 #ifdef vms
  68     sprintf (file, "%s%s", PATH_DATA, YOW_FILE);
  69 #else
  70     sprintf (file, "%s/%s", PATH_DATA, YOW_FILE);
  71 #endif
  72
  73   if ((fp = fopen(file, "r")) == NULL) {
  74     fprintf(stderr, "yow: ");
  75     perror(file);
  76     exit(EXIT_FAILURE);
  77   }
  78
  79   /* initialize random seed */
  80   srand((int) (getpid() + time((time_t *) 0)));
  81
  82   setup_yow(fp);
  83   yow(fp);
  84   fclose(fp);
  85   return EXIT_SUCCESS;
  86 }
  87
  88 static long len = -1;
  89 static long header_len;
  90
  91 #define AVG_LEN 40              /* average length of a quotation */
  92
  93 /* Sets len and header_len */
  94 void
  95 setup_yow(fp)
  96      FILE *fp;
  97 {
  98   int c;
  99
 100   /* Get length of file */
 101   /* Because the header (stuff before the first SEP) can be very long,
 102    * thus biasing our search in favor of the first quotation in the file,
 103    * we explicitly skip that. */
 104   while ((c = getc(fp)) != SEP) {
 105     if (c == EOF) {
 106       fprintf(stderr, "yow: file contains no separators\n");
 107       exit(2);
 108     }
 109   }
 110   header_len = ftell(fp);
 111   if (header_len > AVG_LEN)
 112     header_len -= AVG_LEN;      /* allow the first quotation to appear */
 113
 114   if (fseek(fp, 0L, 2) == -1) {
 115     perror("yow");
 116     exit(EXIT_FAILURE);
 117   }
 118   len = ftell(fp) - header_len;
 119 }
 120
 121
 122 /* go to a random place in the file and print the quotation there */
 123 void
 124 yow (fp)
 125      FILE *fp;
 126 {
 127   long offset;
 128   int c, i = 0;
 129   char *buf;
 130   unsigned int bufsize;
 131
 132   offset = rand() % len + header_len;
 133   if (fseek(fp, offset, 0) == -1) {
 134     perror("yow");
 135     exit(EXIT_FAILURE);
 136   }
 137
 138   /* Read until SEP, read next line, print it.
 139      (Note that we will never print anything before the first separator.)
 140      If we hit EOF looking for the first SEP, just recurse. */
 141   while ((c = getc(fp)) != SEP)
 142     if (c == EOF) {
 143       yow(fp);
 144       return;
 145     }
 146
 147   /* Skip leading whitespace, then read in a quotation.
 148      If we hit EOF before we find a non-whitespace char, recurse. */
 149   while (isspace(c = getc(fp)))
 150     ;
 151   if (c == EOF) {
 152     yow(fp);
 153     return;
 154   }
 155
 156   bufsize = BUFSIZE;
 157   buf = (char *) malloc(bufsize);
 158   if (buf == (char *)0) {
 159     fprintf(stderr, "yow: virtual memory exhausted\n");
 160     exit (3);
 161   }
 162
 163   buf[i++] = c;
 164   while ((c = getc(fp)) != SEP && c != EOF) {
 165     buf[i++] = c;
 166
 167     if (i == bufsize-1) {
 168       /* Yow! Is this quotation too long yet? */
 169       bufsize *= 2;
 170       buf = (char *) realloc(buf, bufsize);
 171       if (buf == (char *)0) {
 172         fprintf(stderr, "yow: virtual memory exhausted\n");
 173         exit (3);
 174       }
 175     }
 176   }
 177   buf[i++] = 0;
 178   printf("%s\n", buf);
 179 }
 180
 181 /* arch-tag: e40fc0df-bafb-4001-af24-5c883d1c685e
 182    (do not change this comment) */
 183
 184 /* yow.c ends here */