CODEWITHSUNDEEP
cpointersfopen
Idan
Idan

Reputation: 227

Trying to get the strings out a txt file in c

for some reason I get exeception after the line:

currentString[i] = *currentChar;

This code is ment to gather all of the the characters from a file, till it encounters the character ';', and put them in a string. Does anyone knows what's the deal? thanks! This is all of the code:

char currentString[100] = { 0 };
char *currentChar;

//opening the input file
FILE *input = fopen("input.txt", "r");
//if the file doesn't exist, the pointer will contain NULL
if (input == NULL)
{
    exit(1);
}

//assigning the start of the input file adress to currentChar
currentChar = input;

//while the current character isn't the last character of the input file
while (currentChar < input + strlen(input) + 1)
{
    while (currentChar != ';')
    {
        currentString[i] = *currentChar;
        printf("%c", *currentChar);
        currentChar = currentChar + 1*sizeof(char);
        i++;
    }
}

Upvotes: 0

Views: 100

Answers (2)

dbush
dbush

Reputation: 223872

You're not reading from the file at all. This:

currentChar = input;

Assigns the address of the FILE object pointed to by input to currentChar. This is also a type mismatch because you're assigning a FILE * to a char *. You also can't use strlen on input because it is not a char *. You should have gotten plenty of compiler warnings about these.

To read characters from a file, use the fgetc function:

int currentChar = fgetc(input);

//while the current character isn't the last character of the input file or a ';'
while (currentChar != EOF && currentChar != ';')
    currentString[i] = currentChar;
    printf("%c", currentChar);
    currentChar = fgetc(input);
    i++;
}

Upvotes: 1

Arkku
Arkku

Reputation: 42129

input is a pointer to an opaque FILE type, not a pointer to the contents the file as you seem to assume. This means you cannot access the contents of the file through the pointer directly. Instead, you need to pass input to functions that read input from the file, such as fgets, getc and fscanf.

Upvotes: 3

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