[R] can't read a file

[Clemence Germaine]

Hi 

It's the first time I use R on mac, before I used on Windows, so I can't have my data when I have the function : read.table, my file is maned : data1.txt
Do I use another format for my file?

And when I trie list.file I have this answer : character(0) but I know where my file is on my computer.

If anybody can help me?

Thanks

Clémence