CODEWITHSUNDEEP
c
Madison Bularia
Madison Bularia

Reputation: 9

Issue getting character in char array at index in C

I'm new to C programming and I've been having a issue in one of my functions which is supposed to get the characters in a char array.

This is my code:

int main()
{
    char javaFileLocation[512];
    char cFileLocation[512];
    char cFileName[512];

    printf("Type in the location of the Java file you'd like to convert : \n\n");
    fgets(javaFileLocation, 512, stdin);
    removeLastChar(javaFileLocation);

    printf("Choose the location you want the resulting C file to be in : \n\n");
    fgets(cFileLocation, 512, stdin);
    removeLastChar(cFileLocation);

    printf("Choose the name for the new C file : \n\n");
    fgets(cFileName, 512, stdin);
    removeLastChar(cFileName);

    FILE * javaFile = fopen(javaFileLocation, "r");
    if(javaFile == NULL) {
       printf("The java file you specified does not exist!: ");
       perror("fopen error: ");
       return 1;
    }
    strcat(cFileLocation, cFileName);
    FILE * cFile = fopen(cFileLocation, "w");
    if(cFile == NULL) {
       printf("The c file was not able to be created!: ");
       perror("fopen error: ");
       return 1;
    }
    printf("file has been successfully created. \n");
    int maxSize = 0;
    char contents[512];
    while (fgets(contents, sizeof(contents), javaFile)) {
        maxSize = maxSize + strlen(contents) + 1;
    }
    char translated[maxSize];
    rewind(javaFile);
    while (fgets(contents, sizeof(contents), javaFile)) {
       getTranslation(contents, translated);
    }
    fprintf(cFile, translated);
    fclose(javaFile);
    fclose(cFile);
    return 0;
}

void removeLastChar(char * word){
    word[strlen(word) - 1] = '\0';
}

void getTranslation(char line[], char translation[]){
    char current[strlen(line)];
    int index;
    for(index = 0; index < strlen(line); index++){
        strcat(translation, line[index + 1]);
    }
}

My issue is happening in getTranslation and is the line strcat(translation, line[index + 1]);. The code runs, but when it reaches that line, the program freezes, does nothing, and I get this as the return code in my console:

Process returned -1073741819 (0xC0000005) execution time : 24.007 s

If anyone knows what's wrong and can help me it'd be greatly appreciated.

Upvotes: 0

Views: 59

Answers (2)

paulsm4
paulsm4

Reputation: 121609

On Windows, (0xC0000005) is an access violation.

This is Bad. It means you're writing outside "legal" memory. It will crash your program.

Among other things, I would modify getTranslation() to ensure that, however often you append (strcat) to "translated", you NEVER exceed 511 characters (remember - you always need to reserve an extra byte for the null termination character).

Upvotes: 1

Davi Doro
Davi Doro

Reputation: 378

Your index goes from 0 to strlen(line), but since you are adding +1 you are effectivelly iterating from 1 to strlen(line), and thus the last iteration will fail when it tries to access line[strlen(line)+1]. But there is a more important issue which has already been pointed out in the comments: strcat takes a const char* as the second argument, but you are passing a char. Does your code even compile?

Upvotes: 0

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