diff options
| -rw-r--r-- | include/str.h | 1 | ||||
| -rw-r--r-- | lib/str.c | 41 |
2 files changed, 42 insertions, 0 deletions
diff --git a/include/str.h b/include/str.h index 5e6d30d..468f674 100644 --- a/include/str.h +++ b/include/str.h @@ -33,5 +33,6 @@ int isempty(char *sptr); int isquoted(char *sptr); char *normalize_space(char *s); char **strdup_array(char **array); +int strcmp_array(const char **a, const char **b); #endif //SPM_STR_H @@ -776,3 +776,44 @@ char **strdup_array(char **array) { return result; } + +/** + * Compare two arrays of strings + * + * `a` and/or `b` may be `NULL`. You should test for `NULL` in advance if _your_ program considers this an error condition. + * + * @param a array of strings + * @param b array of strings + * @return 0 = identical + */ +int strcmp_array(const char **a, const char **b) { + size_t a_len = 0; + size_t b_len = 0; + + // This could lead to false-positives depending on what the caller plans to achieve + if (a == NULL && b == NULL) { + return 0; + } else if (a == NULL) { + return -1; + } else if (b == NULL) { + return 1; + } + + // Get length of arrays + for (a_len = 0; a[a_len] != NULL; a_len++); + for (b_len = 0; b[b_len] != NULL; b_len++); + + // Check lengths are equal + if (a_len < b_len) return (int)(b_len - a_len); + else if (a_len > b_len) return (int)(a_len - b_len); + + // Compare strings in the arrays returning the total difference in bytes + int result = 0; + for (size_t ai = 0, bi = 0 ;a[ai] != NULL || b[bi] != NULL; ai++, bi++) { + int status = 0; + if ((status = strcmp(a[ai], b[bi]) != 0)) { + result += status; + } + } + return result; +} |