gerp(1):ファイルで指定した文字列を検索し、その行を印刷する

/** @autho: yj   
 *  @function: like gerp command in linux: find lines with a specified string in a file, and print these lines.
 *  @usage: ./grep [string] [filename]
 **/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define MAX		100

int strindex(char s[], char t[]);


int main(int argc, char *argv[])
{
	int i;
	char c;
	FILE *fp;
	int found = 0;
	char str[MAX]; // keep a line read from a file
	if(argc < 3) {
		fprintf(stderr, "Not enough arguments
");
		exit(-1);
	}
	if((fp = fopen(argv[2], "r")) == NULL) {
		fprintf(stderr, "File open failed
");
		exit(-1);
	}
	
	/*read one line from a file*/
	while(!feof(fp)) {
		for(i=0; i<MAX-1 && (c = fgetc(fp)) != EOF && c != '
'; i++)
		{
			str[i] = c;
		}
		if(c == '
')
			str[i++] = '
';
		str[i] = '\0';
		//if(c == EOF)
		//	break;
		if(strindex(str, argv[1]) >= 0) {
			printf("%s", str);
			found++;
		}
			
	}
	printf("total lines: %d
", found);
	return found;
}


/*find position of string t[], and return position; if not exist, return -1 */
int strindex(char s[], char t[])
{
	int i, j, k;
	
	for(i=0; s[i] != '\0'; i++) {
		for(j=i, k=0; t[k]!='\0' && s[j]==t[k]; j++, k++)
		;
		if(k > 0 && t[k] == '\0') //t[k] = '\0' means completely similar
			return i;
	}
	return -1;
}