c - 如何将标记化字符串存储到 C 中的数组中

Question

在我的程序中，我读取了一些包含字符串“y'”和“y''”的文本，我想将其存储到名为 lhs[ 100]，其余文本进入 rhs[100]。

我该怎么做？我一直在决定它是否适用于 strstr() 或 strcpy()。

#include <stdio.h>
#include <string.h>

int main() {
    FILE *fin;
    fin = fopen("diffeq.txt", "r");
    char line[100];
    char split[] = " +-";
    char* token;
    char lhs[100];
    char rhs[100];
    int i = 0;

    while (fgets(line, sizeof(line), fin) != NULL)
    {
        for (token = strtok(line, split); token; token = strtok(NULL, split))
        {
            // I need to find from the token the string "y'" and "y''"
            // and store them into array "lhs[100]" and the rest of the
            // contents stored into "rhs[100]"
        }
    }
    fclose(fin);
    return 0;
}

Answer 1

此代码正在处理示例文本。我测试过，效果很好。所以你应该添加 read file to text 语句。另外，如果您想在标记之间添加空格，请从 //token[j++] = ' '; 中删除注释符号:

#include <stdio.h>
#include <string.h>
int main() {
    char text[] = "this is a y' sample y'' text y ynot?";
    int len = strlen(text);
    char token[50];
    char lhs[100];
    char rhs[100];
    int state = 0;
    int i, j = 0;
    token[0] = '\0';
    lhs[0] = '\0';
    rhs[0] = '\0';
    printf("\nlen: %d", len);
    for (i = 0; i < len; i++)
        switch (text[i]) {
        case ' ':
        case '+':
        case '-':
            //token[j++] = ' ';
            token[j] = '\0';
            //printf("\ntoken> %s", token);
            // separator is seen, check the token 
            if (state == 2 || state == 3)
                // token is "y'" or "y''"
                strcat(lhs, token);
            else
                // other token detected
                strcat(rhs, token);
            state = 0;
            j = 0;
            break;
        case 'y':
            token[j++] = text[i];
            if (state == 0)
                // first 'y' is detected
                state = 1;
            else
                state = 0;
            break;
        case '\'':
            token[j++] = text[i];
            if (state == 1)
                // we had token=="y" so now we have token=="y'"
                state = 2;
            else if (state == 2)
                // we had token=="y'" so now we have token=="y''"
                state = 3;
            else state = 0;
            break;
        default:
            token[j++] = text[i];
            state = 0;
            break;
        }
    // check token detection condition for last token
    if (state == 2 || state == 3)
        strcat(lhs, token);
    else
        strcat(rhs, token);

        printf("\n\nlhs> %s\nrhs> %s", lhs, rhs);
}