/*
* looking.c
*
* A sample program using bsearch() library.
*
* looking key [file]...
*
* key: specify an integer value to be searched
* may be in decimal, octal(0...), hex(0x...).
*
* file: specify input files (optional)
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
/*
* structure define for variable length array
*/
#define INITSIZE (16 * sizeof(int))
typedef struct arry {
int cursize;
int nmemb;
int *data;
} array_t;
/*
* add an element to an array pointed to by array_t *a
*/
array_t *add_member(array_t *a, int memb)
{
int *p;
long newsize;
if ((a->nmemb + 1) * sizeof(int) > a->cursize) {
newsize = (long)a->cursize * 2L;
if (newsize >= INT_MAX) {
fprintf(stderr, "too many data\n");
exit(1);
}
a->cursize = (int)newsize;
if ((p = realloc(a->data, (size_t)a->cursize)) != NULL)
a->data = p;
else {
fprintf(stderr, "out of memory\n");
exit(1);
}
}
a->data[a->nmemb++] = memb;
return a;
}
/*
* skip leading spaces.
*/
char *remblank(char *p)
{
while (isspace(*p))
++p;
return p;
}
/*
* get next line and pick integer data from it
*/
#define MAXLINE 1024
array_t *read_array(FILE *fp, array_t *a)
{
char line[MAXLINE];
char *p;
char *endp = NULL; /* make silly lint happy */
int val;
if (a == NULL) {
if ((a = malloc(sizeof(array_t))) == NULL) {
fprintf(stderr, "out of memory %u\n", sizeof(array_t));
exit(1);
}
a->cursize = INITSIZE;
a->nmemb = 0;
if ((a->data = malloc(INITSIZE)) == NULL) {
fprintf(stderr, "out of memory %u", INITSIZE);
exit(1);
}
}
while (fgets(line, sizeof(line), fp) != NULL) {
for (p = remblank(line); *p != '\0'; p = remblank(endp)) {
val = (int)strtol(p, &endp, 0);
if (p == endp) {
fprintf(stderr, "data error: %s", line);
fprintf(stderr, " %*s^\n", endp - line, "");
exit(1);
}
a = add_member(a, val);
}
}
return a;
}
void print_array(array_t *a)
{
int i;
for (i = 0; i < a->nmemb; ++i)
printf("%d\n", a->data[i]);
}
int cmp_int(const void *p0, const void *p1)
{
return *(const int *)p0 - *(const int *)p1;
}
/*
* Mail command driver
*/
int main(int argc, char **argv)
{
FILE *fp;
int i;
int key;
char *endp;
array_t *ary = NULL;
if (argc == 1) { /* no argument */
fprintf(stderr, "useage: looking key [file]...\n");
exit(1);
}
key = (int)strtol(argv[1], &endp, 0);
if (argv[1] == endp) {
fprintf(stderr, "invalid number: %s\n", argv[1]);
exit(1);
}
--argc;
++argv;
if (argc == 1) /* no file is specified */
ary = read_array(stdin, ary);
else {
for (i = 1; i < argc; ++i) {
if ((fp = fopen(argv[i], "r")) == NULL) {
fprintf(stderr, "%s: can't open %s\n",
argv[0], argv[1]);
continue;
}
ary = read_array(fp, ary);
fclose(fp);
}
}
qsort(ary->data, ary->nmemb, sizeof(int), cmp_int);
if (bsearch(&key, ary->data, ary->nmemb, sizeof(int), cmp_int) != NULL)
printf("%d yes\n", key);
else
printf("%d no\n", key);
free(ary->data);
free(ary);
return 0;
}
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