句子中单词倒序的问题

Question

I want to read inputtext.txt line by line and reverse the order of words in each line and print them out (input: hello world,output: world hello). With this code my output is all messed up and I get a runtime error #2 saying the stack around my array "string" is corrupted. I tried resetting the strings to null after each while loop iteration but I still get the same error. Does anybody have any suggestions to get rid of the runtime error or help the code run more smoothly?

int main() {
    FILE *inp,*outp;        //file input and output
    int i,wordcount;                    //define counter variables
    int k = 0,j=0;
    char string[200];       //define string to scan sentence into
    char words[20][20];     //2D string for each word in the sentence
    inp = fopen("inputtext.txt", "r");
    outp = fopen("output.txt", "w");
    if (inp == NULL) {
        printf("File not found.\n");
    }
    else {
        while (!feof(inp)) {

            fgets(string, 1000, inp);
            printf("GOT SENTENCE\n");
            for (i = 0; string[i] != '\0'; i++) {


                if (string[i] == ' ') {
                    words[k][j] = '\0';
                    k++;
                    j = 0;
                }
                else
                {
                    words[k][j] = string[i];
                    j++;
                }

            }

            words[k][j] = '\0';
            wordcount = k;
            for (i = wordcount; i >= 0; i--) {
                printf("%s ", words[i]);
            }
            printf("\n\n");

        }
    }
    return 0;
}

Answer 1

the following proposed code:

1. cleanly compiles
2. properly checks for errors
3. properly outputs error messages to stderr
4. performs the desired functionality
5. properly limits the max length of an input
6. assumes no line in the input file is over 199 characters
7. minimizes the number of times the function: strlen() is called
8. actually writes the reversed sentences to the output file

And now, the proposed code:

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


int main() 
{
    FILE *inp,*outp;        //file input and output
    int wordcount;                    //define counter variables
    int k = 0;
    int j = 0;
    char string[200];       //define string to scan sentence into
    char words[20][20];     //2D string for each word in the sentence

    inp = fopen("inputtext.txt", "r");
    if( !inp )
    {
        perror( "fopen to read: inputtext.txt failed" );
        exit( EXIT_FAILURE );
    }

    outp = fopen("output.txt", "w");
    if( !outp )
    {
        perror( "fopen to write: output.txt failed" );
        // cleanup
        fclose( inp );
        exit( EXIT_FAILURE );
    }


    size_t strLength = strlen( string );

    for (size_t i = 0; i < strLength; i++)
    {
        // remove any trailing newline
        string[ strspn( string, "\n" ) ] = '\0';

        printf("GOT SENTENCE\n");

        for (size_t i = 0; i < strlen(string); i++) 
        {
            if (string[i] == ' ') 
            {
                words[k][j] = '\0';
                k++;
                j = 0;
            }

            else
            {
                words[k][j] = string[i];
                j++;
            }
        }

        words[k][j] = '\0';
        wordcount = k;

        for ( int i = wordcount; i >= 0; i--) 
        {
            printf("%s ", words[i]);
            fprintf( outp, "%s ", words[i] );
        }
        printf("\n\n");
        fprintf( outp, "\n" );
    }

    return 0;
}