👀 Views: 0 💬 Answers: 1 📅 Created: 2025-07-22

C input sscanf fgets

I've been banging my head against this for hours... I'm working with an unexpected scenario while trying to read and parse user input in my C program. I'm using `fgets` to read a line from standard input and then utilizing `sscanf` to extract specific values from the string. However, the values extracted seem to be inconsistent with what I expect. Here's a snippet of my code: ```c #include <stdio.h> #include <stdlib.h> int main() { char input[100]; int number; char text[50]; printf("Enter a number followed by a word: "); if (fgets(input, sizeof(input), stdin) != NULL) { // Attempting to extract an integer and a string from input int parsed = sscanf(input, "%d %s", &number, text); if (parsed != 2) { printf("behavior: Could not parse input. Parsed: %d\n", parsed); } else { printf("Parsed number: %d, Parsed text: %s\n", number, text); } } return 0; } ``` When I run the program and input something like `42 hello`, I expect to see `Parsed number: 42, Parsed text: hello`. However, if I input `42 hello world`, I get `Parsed number: 42, Parsed text: hello`, which is fine. But if I input just `42`, then the program outputs `behavior: Could not parse input. Parsed: 1`. I tried debugging the code by printing the raw `input` string after `fgets`, and it shows `42\n` due to the newline character. Additionally, I tried using `strtok` to remove the newline character before passing it to `sscanf`, but that didn't solve the question. I'm not sure if this is an scenario with how `sscanf` handles input or if it’s something else. Can anyone point me in the right direction? Am I missing something in terms of input validation or handling? This is happening in both development and production on Linux. I'd really appreciate any guidance on this. Could someone point me to the right documentation?