arrays - C 在堆数组中搜索字符串

Question

我使用以下代码在堆上加载一个大型哈希表。 但是我不知道加载后搜索整个数组的正确语法。

我想我可以在最后一个 J 循环中添加一个 strcmp？？

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    int lines_allocated = 128;
    int max_line_len = 100;

    /* Allocate lines of text */
    char **words = (char **)malloc(sizeof(char*)*lines_allocated);
    if (words==NULL)
    {
        fprintf(stderr,"Out of memory (1).\n");
        exit(1);
    }

    FILE *fp = fopen("hashtable.txt", "r");

    if (fp == NULL)
    {
        fprintf(stderr,"Error opening file.\n");
        exit(2);
    }

    int i;

    for (i = 0; 1; i++)
    {
        int j;

        /* Have we gone over our line allocation? */
        if (i >= lines_allocated)
        {
            int new_size;

            /* Double our allocation and re-allocate */
            new_size = lines_allocated*2;
            words = (char **)realloc(words,sizeof(char*)*new_size);

            if (words == NULL)
            {
                fprintf(stderr,"Out of memory.\n");
                exit(3);
            }

            lines_allocated = new_size;
        }

        /* Allocate space for the next line */
        words[i] = malloc(max_line_len);

        if (words[i] == NULL)
        {
            fprintf(stderr,"Out of memory (3).\n");
            exit(4);
        }

        if (fgets(words[i], max_line_len-1,fp) == NULL)
            break;

        /* Get rid of CR or LF at end of line */
        for (j = strlen(words[i]) - 1; j >= 0 && (words[i][j] == '\n' || words[i][j] == '\r')j--);
            words[i][j] = '\0';
        }

    int j;
    for(j = 0; j < i; j++)
    printf("%s\n", words[j]);
    // Search for a string e.g "ffffffffff999999999922222222227777777777" in words[]
    //
    //strcmp ( string, words[j])????
    //
    //
    //
    /* Good practice to free memory */

    for (;i>=0;i--)
        free(words[i]);

    free(words);

    return 0;
}

我尝试在循环中实现 strcmp 但程序出现段错误。 使用这个例子:

/* what is i? the number of items used in the array? */
for(x = 0; x < i; x++) {
    if ( strcmp( new_name, names[x] ) == 0 ){
        /* match, x is the index */
        return x;
    }
}
/* here with no match */
return -1;

Answer 1

当我缩进你的代码时，我看到:

for (j = strlen(words[i]) - 1; j >= 0 && (words[i][j] == '\n' || Words[i][j] == '\r')j--);

我想你的意思是:

for (j = strlen(words[i]) - 1; j >= 0 && (words[i][j] == '\n' || Words[i][j] == '\r'); j--)

----^^^^^^^^

那个 while 永远不会执行大括号之间的内容。