add prog 4

2 files changed, 38 insertions, 0 deletions

diff --git a/4/input b/4/input
new file mode 100644
index 0000000..7f0cc0b
--- /dev/null
+++ b/4/input
@@ -0,0 +1,5 @@
+int main() {
+    int n;
+    printf("hello world");
+    scanf("%d", &n);
+}
diff --git a/4/main.l b/4/main.l
new file mode 100644
index 0000000..f768382
--- /dev/null
+++ b/4/main.l
@@ -0,0 +1,33 @@
+%{
+
+int scans = 0;
+int prints = 0;
+%}
+
+%%
+scanf {
+    scans++;
+    fprintf(yyout, "readf");
+};
+printf {
+    prints++;
+    fprintf(yyout, "writef"); 
+}
+; fprintf(yyout, "%s", yytext);
+\n fprintf(yyout, "\n");
+%%
+
+int main(void) {
+    yyin=fopen("4/input", "r+");
+    yyout=fopen("4/output", "w");
+    yylex();
+    printf("%d printf occurrences\n", prints);
+    printf("%d scanf  occurrences\n", scans);
+}
+
+int yywrap()
+{
+exit(0);
+    return(1);
+}
+