[R] name of the graphics output

[Arnau Mir Torres]

Hello.

In the file list.txt, I have the name of n files in data frame format. I 
want to make an image for each file and save the images in pdf format.

To do this, I do the following:

llista = scan(file="list.txt",what=list(nom=""))
for (file.name in llista[[1]]){
        aux=read.table(file=file.name)
        aux=as.matrix(aux)
        pdf()
        image(aux)
        system("mv Rplots.pdf file.name.pdf")
        dev.off()
}

All is OK except for the command
system("mv Rplots.pdf file.name.pdf").
All the outputs names are file.name.pdf but I want to put a different 
name for each graphic.
I have tried
pdf(file="file.name.pdf") but it doesn't work.

How can I make it?

Thanks,

Arnau.