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author | Nicholas Hall <ngh@grandcare.com> | 2017-09-14 16:42:29 -0500 |
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committer | Nicholas Hall <ngh@grandcare.com> | 2017-09-14 16:42:29 -0500 |
commit | 52e3ab594b34bf309b8669fcaa855c295a00e114 (patch) | |
tree | 464216f7987f6df92d7c2c85bf3d398ef32189ea /src/strcmp.c | |
download | hooking_strcmp-52e3ab594b34bf309b8669fcaa855c295a00e114.tar.xz hooking_strcmp-52e3ab594b34bf309b8669fcaa855c295a00e114.zip |
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; +} |