Strings without <string.h>

[wsme]

Hey all,

Wanting to use char* or char[MAXLEN] as a string as I had in a recent class, but am unable to remember how it was done in the class. I remember most of the control statements regarding the technique (though they are pretty standard and may not be much help), and have included the sample below.

Run-time error at point marked in code

The eventual goal is to search for a string in the str string.

// Finding a part of a string

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

#define MAXLEN 1024
void printStr(char str[]) {
    int i = 0;
    puts("String entered:");
    for (i = 0; str[i] != '\0' && i < MAXLEN; i++) // error occurs here
        printf("%c\n", str[i]);
}

void setString(char str[]) {
    puts("Enter text to be added to string:");
    scanf("%s", &str);
    printStr(str);
}

void findText();

int main(void) {
    char str[MAXLEN];
    setString(str);
//    findText();
    return EXIT_SUCCESS;
}

[jonnin]

you have a pointer mistake.
scanf into &str is wrong, str is already a char* so you are making it char** which is wrong. take the & off, and make sure you don't do that same error elsewhere.

fyi strstr finds a substring in a string or returns null pointer if not found.

[wsme]

Oh thank you. I thought I had a worse issue.

It seems like having a type char** is something the compiler should point out, and my compiler has been known to do weird things in the past. Is there something wrong with it?

[jonnin]

maybe. Be sure you turned on maximum warnings and see if it tells you then. If it does not, try a different compiler. Most (All?!) of the major ones would have caught this issue.

[wsme]

How would I verify that I have maximum warnings on?

Also, I noticed that the null character is equivalent to the space character. How could I get around this? (something with the \n instead?)

[Thomas1965]

How would I verify that I have maximum warnings on?

What compiler / IDE do you use ?

Also, I noticed that the null character is equivalent to the space character

What do you mean? A space has ASCII code 32 and the null character 0.

[wsme]

I use Dev-C++ (which uses gcc) on windows

Ah, my bad. I got the program working besides the fact that the printStr function will not print anything past a space character. In my for loop, I have the exit condition:
str[i] != '\0'
which does not seem to be working properly. What is the error in my logic?

[Thomas1965]

str[i] != '\0' is the proper way.
A problem is that scanf will terminate when it encounters a whitespace.
Better use fgets for your input.
This should work:

// Finding a part of a string

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

#define MAXLEN 1024
void printStr(char str[]) 
{
    int i = 0;
    puts("String entered:");
    for (i = 0; str[i] != '\0' && i < MAXLEN; i++) // error occurs here
        printf("%c\n", str[i]);
}

void setString(char str[]) 
{
    puts("Enter text to be added to string:");
    fgets(str, MAXLEN, stdin);
    printStr(str);
}

void findText();

int main(void) {
    char str[MAXLEN];
    setString(str);
//    findText();
    return EXIT_SUCCESS;
}

[wsme]

@Thomas1965
That worked really well. Thank you for your help!
Out of curiosity, are you self taught? If so, where did you learn this?

[jonnin]

gcc I think wants -Wall -Wextra

at least that is what i use on c++ / g++
your IDE should have a way to enable this.

FWIW I have a 4 year degree and decades of coding. And I turned my back for just a couple of years and found the language has changed so much I barely recognize some of the code people post.

[Thomas1965]

I learned some progarmming 25+ years ago in school. I learned most from the examples that came with Turbo Pascal and Turbo C++ and reading lots of books.

[wsme]

I'll try those, then see how things go from there. Thanks for the help @Thomas1965 and jonnin. Appreciate your help and experience.

It's interesting to see the difference in education everyone has here.