pattern_match_print_line.c

//WAP to print each line of its input file that contains a particular pattern of string of characters
#include <stdio.h>
#define MAXLINE 1000 /* maximum input line length */
int getlline(char line[], int max);
	int strindex(char source[], char searchfor[]);
	char pattern[] = "ould";
	/* pattern to search for */
	/* find all lines matching pattern */
int main()
{
	char line[MAXLINE];
	int found = 0;
	while (getlline(line, MAXLINE) > 0)
		if (strindex(line, pattern) >= 0) {
			printf("\n");
			printf("%s", line);
			found++;
		}
	printf("\n");
	return found;
}
/* getline: get line into s, return length */
int getlline(char s[], int lim)
{
	int c, i;
	i = 0;
	while (--lim > 0 && (c=getchar())!= EOF && c != '\n')
		s[i++] = c;
	if (c == '\n')
		s[i++] = c;
	s[i] = '\0';
	return i;
}
/* strindex: return index of t in s, -1 if none */
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')
			return i;
	}
	return -1;
}