XCode help - specifying the source of stdin

[g4c9z]

I am trying to write a command-line application with XCode.

My application takes input from stdin. The way I normally use it is to use redirection to specify the input file. For example:

program < input.txt

In XCode, this is presumably specified by creating an executable and editing its info, via Project -> Edit Active Executable "...".

But the dialog doesn't explain how to specify where input comes from. Changing the arguments to include "< input.txt" doesn't work, I guess because "<" is a symbol known to the Terminal, and XCode probably bypasses the Terminal. Changing the option to "Use Pipe for standard input/output" seems to have no effect - perhaps there's a way to specify a pipe, but the dialog won't let me. Searching the XCode User's Guide didn't explain it either - it mentions the "Use Pipe" option, but doesn't describe how it works.

How can I get standard input from a file?

[Viro]

Use the C function freopen. You should never bank on the terminal being present and C already has a standard function to do I/O redirection. See http://www.cplusplus.com/reference/c...o/freopen.html for an example of how to use this function.

[g4c9z]

Thanks. Yeah, modifying my program is always an option, and is the workaround I've settled on. It would still be nice to know how the Xcode "pipe" option works though.

[Viro]

Hmm... don't really know the answer to this. Did you manage to find out?

[g4c9z]

No. I just modified my program to take the file as an argument instead of forcing it to be through standard input. It's not a big deal for me, but I imagine there are other people who can't or don't want to do that, and would like to find an answer to my question.