使用 strsep() 删除空格？

Question

我正在尝试读取诸如“ls -la /tmp”之类的命令行，并且需要将它们拆分为字符指针数组。我使用 getline() 读取输入，并将输入和指针数组传递给函数，“i”返回命令/参数的数量，因此在本例中为 3。我希望能够忽略/删除任何空格而不是 seg空行上的错误，例如充满制表符的行，因此每个数组索引将分别指向“ls”，“-la”，“/tmp”。非常感谢任何帮助。

int string_split(char * input, char * commands[]) {
    int i = 0;
    const char * delim = " \t\r\n\a";
    //Remove trailing newline character
    input[strcspn(input, "\n")] = '\0';
    //Break user input into each command using fixed delimiter
    while((commands[i] = strsep(&input, delim)) != NULL) {
        //Each break counted then returned to reference number of command/arguments
        i++;
    }
    return i;
}

更喜欢使用 strsep 而不是 strtok/strtok_r，我已经尝试过这两种方法并不断遇到段错误。

Answer 1

您可以轻松地自己创建这样的功能。

/**
 * @brief Splits a string into substrings using a delimiter.
 *
 * This function splits the input string `str` into substrings based on the provided
 * delimiter string `delim`, and stores pointers to these substrings in the `argv`
 * array. The maximum number of substrings to store is specified by `argvsize`.
 *
 * @param argv [out] An array of pointers to store the substrings.
 * @param argvsize [in] The size of the `argv` array.
 * @param str [in,out] The input string to split. Will be modified during processing.
 * @param delim [in] The delimiter string used to split the input string.
 * @return The number of substrings stored in the `argv` array.
 *
 * @details This function modifies the input string by replacing delimiter characters
 * with null terminators to separate substrings. The `argv` array is populated with
 * pointers to the start of each substring. If there are more substrings than the
 * size of the `argv` array, only the first `argvsize` substrings will be stored.
 *
 * @note The input string `str` will be modified during processing.
 *
 * \code{c}
 * char input[] = "apple,orange,banana,grape";
 * char *substrings[4];
 * size_t num_substrings = ASCII_splitstring(substrings, 4, input, ",");
 * for (size_t i = 0; i < num_substrings; ++i) {
 *     printf("Substring %zu: %s", i, substrings[i]);
 * }
 *
 * // Output:
 * // Substring 0: apple
 * // Substring 1: orange
 * // Substring 2: banana
 * // Substring 3: grape
 * \endcode
 *
 * @see strchr
 */
size_t ASCII_splitstring(char **argv, size_t argvsize, char *str, const char *delim)
{
    size_t pos = 0;
    if(argv && argvsize && str && *str)
    {
        memset(argv, 0, argvsize * sizeof(*argv));
        argv[pos++] = str;
        while(*str)
        {
            if(strchr(delim, *str))
            {
                *str++ = 0;
                argv[pos++] = str;
                if(pos >= argvsize) break;
            }
            else
            {
                str++;
            }
        }
    }
    return pos;
}