1-13: add usage

1 files changed, 11 insertions, 2 deletions

diff --git a/1.6.c b/1.6.c
index 1d4beef..41004ad 100644
--- a/1.6.c
+++ b/1.6.c
@@ -1,7 +1,8 @@
 #include <stdio.h>
+
 #define OUTWORD 0
 #define INWORD  1
-#define MAXWORDLEN 20
+#define MAXWORDLEN 30
 
 int longest(const int *list) {
     int max = 0;
@@ -12,7 +13,14 @@ int longest(const int *list) {
     return max;
 }
 
-int main () {
+void usage() {
+    printf("print a histogram of the lengths of words in stdin (K&R ex 1-13)\n");
+    printf("    vertical axis is frequency\n");
+    printf("    horizontal axis is word length\n");
+}
+
+int main (int argc, char *argv[]) {
+    if (argc > 1) { usage(); return 0;}
 	int c, i, j, wordlen;
 	int ndigit[MAXWORDLEN] = {0};
     wordlen = 0;
@@ -48,4 +56,5 @@ int main () {
     for (j = 0; j < MAXWORDLEN; ++j)
         printf("%3d", j);
     printf("\n");
+    return 0;
 }