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emacs/lib-src/yow.c
Thien-Thi Nguyen 7235a58f70 (setup_yow): Use EXIT_FAILURE in case no separators found.
(yow): Use EXIT_FAILURE in case of memory error.
2005-05-25 14:17:42 +00:00

185 lines
3.7 KiB
C

/*
* yow.c
*
* Print a quotation from Zippy the Pinhead.
* Qux <Kaufman-David@Yale> March 6, 1986
*
* This file is in the public domain because the author published it
* with no copyright notice before the US signed the Bern Convention.
*
* With dynamic memory allocation.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <ctype.h>
#ifdef TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "epaths.h" /* For PATH_DATA. */
#define BUFSIZE 80
#define SEP '\0'
#ifndef YOW_FILE
#define YOW_FILE "yow.lines"
#endif
#ifdef MSDOS
#define rootrelativepath(rel) \
({\
static char res[BUFSIZE], *p;\
strcpy (res, argv[0]);\
p = res + strlen (res);\
while (p != res && *p != '/' && *p != '\\' && *p != ':') p--;\
strcpy (p + 1, "../");\
strcpy (p + 4, rel);\
&res;})
#endif
void yow();
void setup_yow();
int
main (argc, argv)
int argc;
char *argv[];
{
FILE *fp;
char file[BUFSIZ];
if (argc > 2 && !strcmp (argv[1], "-f"))
strcpy (file, argv[2]);
else
#ifdef vms
sprintf (file, "%s%s", PATH_DATA, YOW_FILE);
#else
sprintf (file, "%s/%s", PATH_DATA, YOW_FILE);
#endif
if ((fp = fopen(file, "r")) == NULL) {
fprintf(stderr, "yow: ");
perror(file);
exit(EXIT_FAILURE);
}
/* initialize random seed */
srand((int) (getpid() + time((time_t *) 0)));
setup_yow(fp);
yow(fp);
fclose(fp);
return EXIT_SUCCESS;
}
static long len = -1;
static long header_len;
#define AVG_LEN 40 /* average length of a quotation */
/* Sets len and header_len */
void
setup_yow(fp)
FILE *fp;
{
int c;
/* Get length of file */
/* Because the header (stuff before the first SEP) can be very long,
* thus biasing our search in favor of the first quotation in the file,
* we explicitly skip that. */
while ((c = getc(fp)) != SEP) {
if (c == EOF) {
fprintf(stderr, "yow: file contains no separators\n");
exit(EXIT_FAILURE);
}
}
header_len = ftell(fp);
if (header_len > AVG_LEN)
header_len -= AVG_LEN; /* allow the first quotation to appear */
if (fseek(fp, 0L, 2) == -1) {
perror("yow");
exit(EXIT_FAILURE);
}
len = ftell(fp) - header_len;
}
/* go to a random place in the file and print the quotation there */
void
yow (fp)
FILE *fp;
{
long offset;
int c, i = 0;
char *buf;
unsigned int bufsize;
offset = rand() % len + header_len;
if (fseek(fp, offset, 0) == -1) {
perror("yow");
exit(EXIT_FAILURE);
}
/* Read until SEP, read next line, print it.
(Note that we will never print anything before the first separator.)
If we hit EOF looking for the first SEP, just recurse. */
while ((c = getc(fp)) != SEP)
if (c == EOF) {
yow(fp);
return;
}
/* Skip leading whitespace, then read in a quotation.
If we hit EOF before we find a non-whitespace char, recurse. */
while (isspace(c = getc(fp)))
;
if (c == EOF) {
yow(fp);
return;
}
bufsize = BUFSIZE;
buf = (char *) malloc(bufsize);
if (buf == (char *)0) {
fprintf(stderr, "yow: virtual memory exhausted\n");
exit (EXIT_FAILURE);
}
buf[i++] = c;
while ((c = getc(fp)) != SEP && c != EOF) {
buf[i++] = c;
if (i == bufsize-1) {
/* Yow! Is this quotation too long yet? */
bufsize *= 2;
buf = (char *) realloc(buf, bufsize);
if (buf == (char *)0) {
fprintf(stderr, "yow: virtual memory exhausted\n");
exit (EXIT_FAILURE);
}
}
}
buf[i++] = 0;
printf("%s\n", buf);
}
/* arch-tag: e40fc0df-bafb-4001-af24-5c883d1c685e
(do not change this comment) */
/* yow.c ends here */