Prevent line being printed to command line pipe to file

Question

The title maybe a little confusing.. so here is my attempt of explaining it:

I have a command for my program:

c file1.txt > file2.txt

This command in the commandline takes the first file and pipes the output of the program (that is printed) to the second file.

So im scanning a user message in:

printf("Enter a message:");
char *message = malloc(sizeof(char) * 256);
scanf("%s", message);
printf("Your message is: %s", message);

But this prints both printf(...) statements to my piped file, whereas I only want the second one. How can i prevent this?

Thanks!

Possible duplicate of [Write to .txt file?](http://stackoverflow.com/questions/11573974/write-to-txt-file) — LPs, Feb 05 '16 at 14:16

score 2 · Accepted Answer · answered Feb 05 '16 at 14:16

2

One way is to use stderr for the information you don't want copied to the output file:

fprintf(stderr, "Enter a message:");

answered Feb 05 '16 at 14:16

Klas Lindbäck

That does not work, it still prints that to the ouput file – madcrazydrumma Feb 05 '16 at 14:20
1

@madcrazydrumma: What? This definitely should *not* be the case for the piping statement as per your question. – alk Feb 05 '16 at 14:21
@alk it still writes to the file, i dont want to print it to the file – madcrazydrumma Feb 05 '16 at 14:24
2

Nevermind, i had other print statements with the same strings, thanks! – madcrazydrumma Feb 05 '16 at 14:25

1 Answers1