diff options
Diffstat (limited to 'src/strcmp.c')
-rw-r--r-- | src/strcmp.c | 27 |
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; +} |