Question

How do you read in a file from stdin?

I need to include the text file to be read when compiling so I can't hard code a specific file name in my code.

This code grabs a line from a file:
fgets(inputLine, MAX_LENGTH, stdin)

the 3rd parameter is the file pointer. However just stdin does not work, I must include something else to get it to read a line. What am I missing?

Example of line when compiling:

clang -Wall readInFile < textFile.txt

Answer 1

This confuses me because stdin is expressly designed to work just like any other FILE*. Like, it's part of the point of the c library that it works like that.

Are you sure your command line isn't what is doing it?

Answer 2

I was using a Makefile, but since I didn't want to add the file in just yet I just did it on one line. I actually compile three programs at once.

Compiling line:

clang -Wall something.h something.c main.c < textFile.txt

When I run, the program will just get stuck in a loop when trying to read the textFile. I put a printf in the loop and nothing was being printed out like it should have.

Answer 3

Wait, are you trying to put in the text file at compile-time? You can't do that. You have to compile it and then run it with textFile.txt fed to it.

Answer 4

I totally forgot that was how you did it >_< thanks!