System Programming in Perl

But what if you do care?

I said that ls doesn't have to know or care that its output is redirected

But some commands do care

For example, ls

ls at the terminal:

        CGI         Flags-Double     MSI         NYLUG-Hardware  intro          rspier
        CGI-TOM     Fleet            Makefile    PROM            lambda         tie
        CSHL-Flags  HandsOn          Menu        TieFile         memoize-brief  typing
        Cassens     LISA             NIH-Flags   UNIX-INTERNALS  memoize-quant
        EXT2FS      MS-intermediate  NIH-Tricks  beg-demo        qrpff

ls to a file:

        CGI
        CGI-TOM
        CSHL-Flags
        Cassens
        EXT2FS
        Flags-Double
        Fleet
        ...
        tie
        typing