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-rw-r--r--src/strcmp.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/src/strcmp.c b/src/strcmp.c
new file mode 100644
index 0000000..d626bd3
--- /dev/null
+++ b/src/strcmp.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+/* Compare S1 and S2, returning less than, equal to or
+ greater than zero if S1 is lexicographically less than,
+ equal to or greater than S2. */
+int strcmp (const char *p1, const char *p2)
+{
+ const unsigned char *s1 = (const unsigned char *) p1;
+ const unsigned char *s2 = (const unsigned char *) p2;
+ unsigned char c1, c2;
+
+ // print out input values
+ printf("strcmp('%s', '%s')", p1, p2);
+ do
+ {
+ c1 = (unsigned char) *s1++;
+ c2 = (unsigned char) *s2++;
+ if (c1 == '\0') {
+ // print return value
+ printf(" = %d\n", c1 - c2);
+ return c1 - c2;
+ }
+ }
+ while (c1 == c2);
+
+ printf(" = %d\n", c1 - c2);
+ return c1 - c2;
+}