Three Cats
thenewsh.blogspot.com
thenewsh.blogspot.com
Counter-point: If cat is becoming your performance bottleneck, you're doing it wrong: http://sial.org/howto/shell/useless-cat/
Yes, the GNU version looks dreadful, but I think that really doesn't matter that much.
EDIT: Well, I guess I didn't consider the case where you want to put cat in a chroot jail. On Solaris 10:
$ ldd /usr/bin/cat
libc.so.1 => /lib/libc.so.1
libm.so.2 => /lib/libm.so.2
/platform/SUNW,T5240/lib/libc_psr.so.1
libnsl.so.1 => /lib/libnsl.so.1
libc.so.1 => /lib/libc.so.1
libmp.so.2 => /lib/libmp.so.2
libmd.so.1 => /lib/libmd.so.1
libscf.so.1 => /lib/libscf.so.1
libdoor.so.1 => /lib/libdoor.so.1
libuutil.so.1 => /lib/libuutil.so.1
libgen.so.1 => /lib/libgen.so.1
libm.so.2 => /lib/libm.so.2
/platform/SUNW,T5240/lib/libc_psr.so.1
/platform/SUNW,T5240/lib/libmd_psr.so.1
[rupert] ~$ ldd $(which cat)
libintl.so.3 => /lib/libintl.so.3
libiconv.so.2 => /lib/libiconv.so.2
libc.so.1 => /lib/libc.so.1
libsocket.so.1 => /lib/libsocket.so.1
libgcc_s.so.1 => /lib/libgcc_s.so.1
libsec.so.1 => /lib/libsec.so.1
libnsl.so.1 => /lib/libnsl.so.1
libavl.so.1 => /lib/libavl.so.1
libidmap.so.1 => /usr/lib/libidmap.so.1
libmp.so.2 => /lib/libmp.so.2
libmd.so.1 => /lib/libmd.so.1
libscf.so.1 => /lib/libscf.so.1
libldap.so.5 => /usr/lib/libldap.so.5
libresolv.so.2 => /lib/libresolv.so.2
libsldap.so.1 => /usr/lib/libsldap.so.1
libuutil.so.1 => /lib/libuutil.so.1
libgen.so.1 => /lib/libgen.so.1
libsasl.so.1 => /usr/lib/libsasl.so.1
libnspr4.so => /usr/lib/libnspr4.so
libplc4.so => /usr/lib/libplc4.so
libnss3.so => /usr/lib/libnss3.so
libssl3.so => /usr/lib/libssl3.so
librt.so.1 => /lib/librt.so.1
libdl.so.1 => /lib/libdl.so.1
libsoftokn3.so => /usr/lib/libsoftokn3.so
libplds4.so => /usr/lib/libplds4.so
libm.so.2 => /lib/libm.so.2
$ otool -L /bin/cat
/bin/cat:
/usr/lib/libSystem.B.dylib
$ otool -L /usr/lib/libSystem.B.dylib
/usr/lib/libSystem.B.dylib:
/usr/lib/libSystem.B.dylib
/usr/lib/system/libmathCommon.A.dylib
$ otool -L /usr/lib/system/libmathCommon.A.dylib
/usr/lib/system/libmathCommon.A.dylib:
/usr/lib/system/libmathCommon.A.dylib $ ldd /bin/cat
linux-vdso.so.1 => (0x00007ffff71ff000)
libc.so.6 => /lib/libc.so.6 (0x00007f5ef56ec000)
/lib64/ld-linux-x86-64.so.2 (0x00007f5ef5a71000)Solaris used to have one that was a shell script that contained only copyright header comments and no code. The current OpenSolaris one looks sane: http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/sr...
"Why are (OUTSIZE - 1 + INSIZE * 4 + LINE_COUNTER_BUF_LEN + PAGE_SIZE - 1) bytes allocated for the output buffer?"
Then it goes on a 15 lines article, divided in two paragraphs, explaining the reasoning behind the code.
cat --vet
I actually use this feature and am grateful for it's existence.