# <stdio.h>

**[<stdio.h>](https://en.cppreference.com/w/c/header/stdio)** provides buffered file and console I/O: `printf`, `scanf`, `fopen`, `fclose`, and stream operations. Use `snprintf` instead of `sprintf` to avoid buffer overflows; always check return values.

Compile with `-lm` if using math functions; I/O functions link with the C library automatically.

## Example

This example opens a file, writes formatted data, seeks, and reads it back.

```c
// compile: gcc -o studioexample studioexample.c
// run: ./studioexample
// description: write to file, seek to start, read back line by line

#include <stdio.h>

int main() {
    FILE* f = fopen("/tmp/stdio.txt", "w+");
    if (!f) { perror("fopen"); return 1; }
    
    fprintf(f, "line 1\n");
    fprintf(f, "line 2\n");
    fprintf(f, "line 3\n");
    
    rewind(f);
    
    char buf[64];
    while (fgets(buf, sizeof(buf), f))
        printf("read: %s", buf);
    
    fclose(f);
    return 0;
}
```