CAT

Felis domestica, a small animal that usually lives in house provided by its staff.

Felis Felis sylvestris catus, from an alternate (and detailed) phylogeny (at least you can see why cat). See http://www.fmnh.helsinki.fi/users/haaramo/Metazoa/Deuterostoma/Chordata/Synapsida/Eutheria/Carnivora/Aeluroidea/Felinae.htm for more...

cat, a small utility that usually lives in bin provided by root's staff. PBO The name is said to be an abbrev. of concatenate, which is one of cat's uses.

Here's a partial reimplementation in Tcl from Playing Bourne shell (it does not write to stdout, but returns its results, for the caller to process further):

 proc cat files {
    set res ""
    foreach file [eval glob $files] {
        set fp [open $file]
        append res [read $fp [file size $file]]
        close $fp
    }
    set res
 } ;# RS

See computer-assisted translation

LV Too often, I see script writers misuse cat. For instance, they might write:

 cat abc | program1

While there are certainly times when cat-ing into a pipeline is the right things to do, this particular, simple, use is typically better written as

  program1 < abc

or, if program1 supports it

 program1 abc