diff options
| -rw-r--r-- | include/str.h | 1 | ||||
| -rw-r--r-- | src/str.c | 59 |
2 files changed, 60 insertions, 0 deletions
diff --git a/include/str.h b/include/str.h index 06e4a77..23126ab 100644 --- a/include/str.h +++ b/include/str.h @@ -11,6 +11,7 @@ void strdelsuffix(char *sptr, const char *suffix); char** split(char *sptr, const char* delim); void split_free(char **ptr); char *join(char **arr, const char *separator); +char *join_ex(char *separator, ...); char *substring_between(char *sptr, const char *delims); void strsort(char **arr); int find_in_file(const char *filename, const char *pattern); @@ -251,6 +251,65 @@ char *join(char **arr, const char *separator) { } /** + * Join two or more strings by a `separator` string + * @param separator + * @param ... + * @return string + */ +char *join_ex(char *separator, ...) { + va_list ap; // Variadic argument list + size_t separator_len = 0; // Length of separator string + size_t size = 0; // Length of output string + size_t argc = 0; // Number of arguments ^ "..." + char **argv = NULL; // Arguments + char *current = NULL; // Current argument + char *result = NULL; // Output string + + // Initialize array + argv = calloc(argc + 1, sizeof(char)); + if (argv == NULL) { + perror("join_ex calloc failed"); + return NULL; + } + + // Get length of the separator + separator_len = strlen(separator); + + // Process variadic arguments: + // 1. Iterate over argument list `ap` + // 2. Assign `current` with the value of argument in `ap` + // 3. Extend the `argv` array by the latest argument count `argc` + // 4. Sum the length of the argument and the `separator` passed to the function + // 5. Append `current` string to `argv` array + // 6. Update argument counter `argc` + va_start(ap, separator); + for(argc = 0; (current = va_arg(ap, char *)) != NULL; argc++) { + char **tmp = realloc(argv, (argc + 1) * sizeof(char *)); + if (tmp == NULL) { + perror("join_ex realloc failed"); + return NULL; + } + argv = tmp; + size += strlen(current) + separator_len; + argv[argc] = strdup(current); + } + va_end(ap); + + // Generate output string + result = calloc(size, sizeof(char)); + for (size_t i = 0; i < argc; i++) { + // Append argument to string + strcat(result, argv[i]); + + // Do not append a trailing separator when we reach the last argument + if (i < (argc - 1)) { + strcat(result, separator); + } + } + + return result; +} +/** * Extract the string encapsulated by characters listed in `delims` * * ~~~{.c} |