13-11.txt

c primer 部分习题答案

PE 13-11
 
/* Programming Exercise 13-11 */
 
#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */
 
#define SLEN 256
const char *errmesg[] = {"Usage: %s string filename]\n",
                         "Can't open file %s\n" };
            
int main(int argc, char *argv[])
{
    FILE *fp;
    char line[SLEN];
 
    argc = ccommand(&argv);   /* Macintosh adjustment */  
    if (argc != 3)
    {
        fprintf(stderr, errmesg[0], argv[0]);
        exit(EXIT_FAILURE);
    }
 
    if ((fp = fopen(argv[2], "r")) == NULL)
    {
        fprintf(stderr, errmesg[1], argv[2]);
        exit(EXIT_FAILURE);
    }
    
    while (fgets(line, SLEN - 1, fp) != NULL)
    {
        if (strstr(line, argv[1]) != NULL)
            fputs(line, stdout);
    }
        
    fclose(fp);
 
    return 0;
}