Reading from a file

[warped gale]

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[gray solar]

That's not how you use fgets.

[lime tendon]

eh how then

i thought numbers is my puffer

max count to read is 100

and file is my file from which i read

[gray solar]

fgets reads a string.

numbers is not a string.

[lime tendon]

int main(int argc, char *argv[]) {
    char dateiname[255];
    float numbers[1000];

    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }

    FILE *file = fopen(dateiname, "r");

    while (fgets(numbers, 10 , file)) {
        fputs(dateiname, stdout);
    }

    for (int i = 0; i < 30; i++) {
        printf("%f\n", numbers[i]);
    }

    return  0;
}

have it like this now

[gray solar]

That still doesn't address the issue.

[lime tendon]

int main(int argc, char *argv[]) {
    char dateiname[255];
    char *numbers[1000];

    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }

    FILE *file = fopen(dateiname, "r");

    while (fgets(numbers, 10 , file)) {
        fputs(dateiname, stdout);
    }

    for (int i = 0; i < 30; i++) {
        printf("%s\n", numbers[i]);
    }

    return  0;
}

so a array of a string

this is my output

[gray solar]

You read into one string, not an array of them.

[lime tendon]

int main(int argc, char *argv[]) {
    char dateiname[255];
    char *numbers[1000];

    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }

    FILE *file = fopen(dateiname, "r");

    while (fgets(*numbers, 10 , file)) {
        fputs(dateiname, stdout);
    }

    for (int i = 0; i < 30; i++) {
        printf("%s\n", numbers[i]);
    }

    return  0;
}

like this

output still the same

[gray solar]

The array is not initialized.

Honestly you need to read about how to use strings.

[lime tendon]

 char *numbers[1000] = {};

do you have any recommendations

quite new but we need to know all that stuff

we only have 2 weeks for a fkn c exam

[gray solar]

https://learn-c.org/en/Strings

[lime tendon]

thanks can you maybe help me solve this issue?

i initialized it

[gray solar]

You initialized it but with unusable values.

You read into one string, not an array of them.
This is key. You don't need an array of strings.

[lime tendon]

this is the layout of my input file

i thought i want them all read in whhere a newline is a new string

[gray solar]

The string is only used once.

With this kind of file though fscanf suffices.

[lime tendon]

int main(int argc, char *argv[]) {
    char dateiname[255];
    char numbers[1000] = {};

    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }

    FILE *file = fopen(dateiname, "r");

    while (fgets(numbers, 10 , file)) {
        fputs(dateiname, stdout);
    }

    for (int i = 0; i < 30; i++) {
        printf("%c\n", numbers[i]);
    }

    return  0;
}

now i dont have an array of chars anymore

what will fgets write into the buffer?

[gray solar]

numbers is an array of chars.

[lime tendon]

what does it need to be

[gray solar]

Like that.

You got it correct.

[lime tendon]

jeah so where does it read the input from the file

does he safe it in this array?

[gray solar]

It stores the characters into the numbers array.

[lime tendon]

but they are float numbers

[gray solar]

They are not floats.

[lime tendon]

e.g. one line is 1.323

how can he safe 1.323 in a char?

[gray solar]

The first character is 1, the next is .,...

[lime tendon]

even if it gets written as char and not fload

jeah

[gray solar]

So now to get a float you need to parse the string.

[lime tendon]

isnt it possible to read in a whole line?

and not every single char

[gray solar]

You are already reading in a whole line.

A line consists of characters.

[lime tendon]

ah

so for every loop

he reads in

1 line as single characters

[gray solar]

A string is an array of characters. A line is a string.

The string 1.323 consists of 5 characters: 1, ., 3, 2, 3.

[lime tendon]

jeah i know that

 char numbers[1000] = {};

    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }

    FILE *file = fopen(dateiname, "r");

    while (fgets(numbers, 10 , file)) {
        fputs(numbers, file);
    }

fgets takes the buffer, max, and a file to get the characters from

[warped gale]

@lime tendon Has your question been resolved? If so, type !solved :)

[lime tendon]

got it kinda working now

int main(int argc, char *argv[]) {
    char dateiname[255];
    char numbers[1000] = {};
    FILE *file;
    if (argv[1] == NULL) {
        printf("Bitte geben sie einen Dateinamen ein\n");
        scanf("%s", dateiname);
    }
    
    file = fopen(dateiname, "r");
    while (fgets(numbers, 10 , file) != NULL) {
        puts(numbers);

    }

    for (int i = 0; i < 10; i++) {
        printf("%c", numbers[i]);
    }

    fclose(file);

    return  0;
}

output is like this

but im asking myself how is the last for loop working

it should only print a "c" but it kinda prints a whole string?

[lime tendon]

so weird?

[lime tendon]

noone?