update

4.1.c

@@ -0,0 +1,44 @@
+#include<stdio.h>
+#define MAXLINE 1000 /* maximum input line length */
+
+int getline(char line[],int max);
+int strindex(char source[],char searchrfor[]);
+
+char pattern[] ="ould";  /* pattern to search for */
+
+/* find all lines matching pattern */
+main() {
+    char line[MAXLINE];
+    int found=0;
+
+    while(getline(line,MAXLINE)>0)
+        if(strindex(line,pattern)>=0) {
+            printf("%s",line);
+            found++;
+        }
+    return found;
+}
+
+/* getline: get line into s, return length */
+int getline(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;
+}