Initial commit

1 files changed, 99 insertions, 0 deletions

diff --git a/str.c b/str.c
new file mode 100644
index 0000000..5469e73
--- /dev/null
+++ b/str.c
@@ -0,0 +1,99 @@
+//
+// Created by jhunk on 3/21/26.
+//
+
+#include "str.h"
+
+int num_chars(const char *sptr, int ch) {
+    int result = 0;
+    for (int i = 0; sptr[i] != '\0'; i++) {
+        if (sptr[i] == ch) {
+            result++;
+        }
+    }
+    return result;
+}
+
+char** split(char *_sptr, const char* delim, size_t max, size_t *num)
+{
+    // Zero the number of elements in the result
+    int have_num = num != NULL;
+    if (have_num) {
+        *num = 0;
+    }
+
+    if (_sptr == NULL || delim == NULL) {
+        return NULL;
+    }
+    size_t split_alloc = 0;
+    // Duplicate the input string and save a copy of the pointer to be freed later
+    char *orig = _sptr;
+    char *sptr = strdup(orig);
+
+    if (!sptr) {
+        return NULL;
+    }
+
+    // Determine how many delimiters are present
+    for (size_t i = 0; i < strlen(delim); i++) {
+        if (max && i > max) {
+            break;
+        }
+        split_alloc += num_chars(sptr, delim[i]);
+    }
+
+    // Preallocate enough records based on the number of delimiters
+    char **result = calloc(split_alloc + 2, sizeof(result[0]));
+    if (!result) {
+        free(sptr);
+        sptr = NULL;
+        return NULL;
+    }
+
+    // No delimiter, but the string was not NULL, so return the original string
+    if (split_alloc == 0) {
+        result[0] = sptr;
+        return result;
+    }
+
+    // Separate the string into individual parts and store them in the result array
+    char *token = NULL;
+    char *sptr_tmp = sptr;
+    size_t pos = 0;
+    size_t i;
+    for (i = 0; (token = strsep(&sptr_tmp, delim)) != NULL; i++) {
+        // When max is zero, record all tokens
+        if (max > 0 && i == max) {
+            // Maximum number of splits occurred.
+            // Record position in string
+            pos = token - sptr;
+            break;
+        }
+        result[i] = calloc(BUFSIZ, sizeof(char));
+        if (!result[i]) {
+            return NULL;
+        }
+        strcpy(result[i], token);
+    }
+
+    // pos is non-zero when maximum split is reached
+    if (pos) {
+        // append the remaining string contents to array
+        result[i] = calloc(BUFSIZ, sizeof(char));
+        if (!result[i]) {
+            return NULL;
+        }
+        strcpy(result[i], &orig[pos]);
+        i++;
+    }
+
+    if (have_num) {
+        // Count of elements in the array
+        *num = i;
+    }
+
+    free(sptr);
+    sptr = NULL;
+    return result;
+}
+