如何从文本文件中获取字符串到C中的数组

Question

I am trying to read a list of strings from a text file and put that into an array with n words.If instead of all the lines of text I need only the first two, I would make my array of size 2 and set n = 2. However when I pass the number of words in as an argument I receive a segmentation fault, if n is not equal to the number of words in the list, and the entire list will still print. How can I control how many words my array will hold while keeping track of my next string in the list?

My text file looks like this: AH12M8 N\\n AD34FU O\\n APD83H O\\n LKFU29 N\\n

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, const char * argv[])
{
    FILE *myfile;
    myfile = fopen("Test.txt", "r");
    char *numWords;
    long n = strtol(argv[1], &numWords, 10);

    if(argc != 2)
   {
        printf("Too Few Arguments");
   }
   else
   {
        char arr[n][100];
        int i = 0;
        while(fgets(arr[i],sizeof(arr),myfile)!=NULL)
        {
            arr[i][strlen(arr[i])-1] = '\0';
            i++;
        }
        int total = i;
        for(i = 0; i < total; ++i)
        {
           printf("%s\n", arr[i]);
        }
        fclose(myfile);
    }
    return 0;
}

Answer 1

 while(fscanf(myfile,"%[^\n]%*c",arr[i])==1)    
    {
        arr[i][strlen(arr[i])-1] = '\0';
        i++;
    }

And check value of argc before using argv[1] .

Answer 2

One problem is that you only allocate space for n strings, but then you read the entire file -- so if there are more than n lines, you run off the end of your array and corrupt memory and likely crash. Another problem is that you're giving fgets the length of the ENTIRE array, not the length of a single string, so if any lines are longer than 99 characters, you run off into then next line (or off the end and crash). Fixing both problems is relatively easy:

    char arr[n][100];
    int i = 0;
    while(i < n && fgets(arr[i], sizeof(arr[i]), myfile) != NULL)
    {
        if (arr[i][strlen(arr[i])-1) == '\n')
            arr[i][strlen(arr[i])-1] = '\0';
        i++;
    }

I also changed it to only drop the last character if it is a newline -- if you have any input lines longer than 99 characters, they'll be split into multiple lines.