// 2025-08-10a
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

unsigned char gi_str_uc[256] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255};
unsigned char gi_str_lc[256] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255};

char* x_sfn_str_cat(char* ps_1, char* ps_2) {
	// 2021-09-01
	long	i_len;
	i_len = strlen(ps_1)+strlen(ps_2)+1;
	char* 	ps_r = malloc(i_len);
	strcpy(ps_r,ps_1);
	strcat(ps_r,ps_2);
	return(ps_r);
}
char* x_sfn_str_upper(char* ps_1) {
	// 2021-12-21
	long i_len = strlen(ps_1)+1;
	char* ps_r = malloc(i_len);
	strcpy(ps_r,ps_1);
   	unsigned long i;
	unsigned char j;
   	for (i = 0; ps_r[i] != 0; i++) {
		j = ps_r[i];
		ps_r[i] = gi_str_uc[j];
   	}
	ps_r[i_len] = 0;
	return(ps_r);
}
void x_fn_str_upper(char* ps_1) {
	// 2021-12-21
   	unsigned long i;
	unsigned char j;
   	for (i = 0; ps_1[i] != 0; i++) {
		j = ps_1[i];
		ps_1[i] = gi_str_uc[j];
   	}
}
char* x_sfn_str_lower(char* ps_1) {
	// 2021-12-21
	long i_len = strlen(ps_1)+1;
	char* ps_r = malloc(i_len);
	strcpy(ps_r,ps_1);
   	unsigned long i;
	unsigned char j;
   	for (i = 0; ps_r[i] != 0; i++) {
		j = ps_r[i];
		ps_r[i] = gi_str_lc[j];
   	}
	ps_r[i_len] = 0;
	return(ps_r);
}
void x_fn_str_lower(char* ps_1) {
	// 2021-12-21
   	unsigned long i;
	unsigned char j;
   	for (i = 0; ps_1[i] != 0; i++) {
		j = ps_1[i];
		ps_1[i] = gi_str_lc[j];
   	}
}
char* x_sfn_str_left(char* ps_1, unsigned long pi) {
	// 2021-12-21
	unsigned long i_len = strlen(ps_1);
	if ( i_len < pi ) { pi = i_len; }
	char* ps_r = malloc(pi+1);
	strncpy(ps_r,ps_1,pi);
	ps_r[pi] = 0;
	return(ps_r);
}
char* x_sfn_str_right(char* ps_1, unsigned long pi) {
	// 2021-12-21
	unsigned long i_len = strlen(ps_1);
	if ( i_len < pi ) { pi = i_len; }
	char* ps_r = malloc(pi+1);
	strncpy(ps_r,&ps_1[i_len-pi],pi);
	ps_r[pi] = 0;
	return(ps_r);
}
void x_fn_str_reverse(char* ps_1) {
	// 2021-12-21
	char c;
	unsigned long i;
	unsigned long i_len = strlen(ps_1);
	unsigned long i_len_half = (i_len/2);
	for (i = 0; i < i_len_half; i++) {
		c = ps_1[i];
		ps_1[i] = ps_1[i_len - i - 1];
		ps_1[i_len - i - 1] = c;
	}
}
char* x_sfn_str_reverse(char* ps_1) {
	// 2021-12-21
	unsigned long i;
	unsigned long i_len = strlen(ps_1);
	unsigned long i_len_half = (i_len/2);
	char* ps_r = malloc(i_len+1);
	for (i=0; i < i_len_half; i++) {
		ps_r[i] = ps_1[i_len - i - 1];
		ps_r[i_len - i - 1] = ps_1[i];
	} 
	if ((i_len % 2) == 1) {
		ps_r[(i_len_half)] = ps_1[(i_len_half)];
	}
	ps_r[i_len] = 0;
	return(ps_r);
}
char* x_sfn_str_left_chr(char* ps_1, char c) {
	// 2021-12-21
	unsigned long i_len = strlen(ps_1);
	char* s_2 = strchr(ps_1,c);
	unsigned long i = 0;
	char* ps_r = NULL;
	if (s_2 != NULL) {
		i = s_2 - ps_1;
		if (i_len < i) {i = i_len;}
		ps_r = malloc(i+1);
		strncpy(ps_r,ps_1,i);
		ps_r[i] = 0;
	}
	return(ps_r);
}
char* x_sfn_str_right_chr(char* ps_1, char c) {
	// 2021-12-21
	// unsigned long i_len = strlen(ps_1);
	char* s_2_alloc = strdup(ps_1);
	x_fn_str_reverse(s_2_alloc);
	char* ps_r = x_sfn_str_left_chr(s_2_alloc,c);
	if ( ps_r != NULL ) {
		x_fn_str_reverse(ps_r);
	}
	free(s_2_alloc);
	return(ps_r);
}
long x_ifn_str_index_chr(char* ps_1, char c) {
	char* s_2 = strchr(ps_1,c);
	unsigned long i_r = -1;
	if (s_2 != NULL) {
		i_r = s_2 - ps_1;
	}
	return(i_r);
}
long x_ifn_str_index(char* ps_1, char* ps_2) {
	char* s_2 = strstr(ps_1,ps_2);
	unsigned long i_r = -1;
	if (s_2 != NULL) {
		i_r = s_2 - ps_1;
	}
	return(i_r);
}
char* x_sfn_str_substr(char* ps_1, long pi_idx, long pi_len ) {
	unsigned long i_idx = pi_idx;
	unsigned long i_len = strlen(ps_1);
	if ( pi_idx < 0 ) {
		i_idx = i_len + pi_idx;
		i_len = 0 - pi_idx;
	} else {
		i_len = i_len - pi_idx;
	}
	if ( pi_len < 1 ) {
		i_len = i_len + pi_len;
	} else {
		i_len = pi_len;
	}
	char* ps_r = malloc(i_len+1);
	strncpy(ps_r,&ps_1[i_idx],i_len);
	ps_r[i_len] = 0;
	return(ps_r);
}
unsigned long x_ifn_str_replace_chr( char* ps, char ps_find, char ps_replace ) {
	// 2025-08-10
	// Replace all occurences of a single character {ps_find} in string {ps} with a single character {ps_replace}
	// - modifies the supplied string
	// - returns number of replacements made 
	unsigned long i_count = 0;
    char *s_pos = strchr( ps, ps_find );
    while ( s_pos ) {
		i_count++;
        *s_pos = ps_replace;
        s_pos = strchr (s_pos + 1, ps_find);
    }
    return( i_count );
}