###sh, bash

cc cc: no input files 

cc rotated is cc again, but it is not very friendly if called so naked.

dh dh: cannot read debian/control: No such file or directory hd 

dh debhelper isn't very cooperative too, while hexdump just waits for input.

gs sg 

Ghostscript starts interactive mode, while switch group shows a usage message - a valid solution here, imho, too.

And here is the script to find candidates for such programs:

#!/bin/bash for name in /sbin/* /usr/sbin/* /bin/* /usr/bin/* do len=${#name} # len=3 => 1:2 0:1, 2:1 0:2 # len=4 => 1:3 0:1, 2:2 0:2, 3:1 0:3 for n in $(seq 1 $((len-1))) do init=${name:n:len-n} rest=${name:0:n} # echo $init$rest which /usr/bin/$init$rest 2>/dev/null >/dev/null && echo $name $init$rest $n done done 

If finds longer sequences too, like (arj, jar) or (luatex, texlua) which aren't valid after every shift, but only after some certain shifts, which I misread in the beginning, but there are few, so it is easy to filter them out by hand.

sh, bash

cc cc: no input files 

cc rotated is cc again, but it is not very friendly if called so naked.

dh dh: cannot read debian/control: No such file or directory hd 

dh debhelper isn't very cooperative too, while hexdump just waits for input.

gs sg 

Ghostscript starts interactive mode, while switch group shows a usage message - a valid solution here, imho, too.

And here is the script to find candidates for such programs:

#!/bin/bash for name in /sbin/* /usr/sbin/* /bin/* /usr/bin/* do len=${#name} # len=3 => 1:2 0:1, 2:1 0:2 # len=4 => 1:3 0:1, 2:2 0:2, 3:1 0:3 for n in $(seq 1 $((len-1))) do init=${name:n:len-n} rest=${name:0:n} # echo $init$rest which /usr/bin/$init$rest 2>/dev/null >/dev/null && echo $name $init$rest $n done done 

If finds longer sequences too, like (arj, jar) or (luatex, texlua) which aren't valid after every shift, but only after some certain shifts, which I misread in the beginning, but there are few, so it is easy to filter them out by hand.

###sh, bash

arj jar 

Arj and jar present, without parameters, a usage message, each different from the other. Valid solution, imho.

cc cc: no input files 

cc rotated is cc again, but it is not very friendly if called so naked.

dh dh: cannot read debian/control: No such file or directory hd 

dh debhelper isn't very cooperative too, while hexdump just waits for input.

gs sg 

Ghostscript starts interactive mode, while switch group shows a usage message - a valid solution here, imho, too.

luatex texlua luatex This is LuaTeX, Version beta-0.50.0-2010010503 **! End of file on the terminal... why? texlua No script file given 

Both look friendly, one is interactive. Valid, imho.

ps2ps2 ps2ps2 Usage: ps2ps2 [options] input.ps output.ps e.g. ps2ps2 -sPAPERSIZE=a4 input.ps output.ps 

A friendly selfrotater too.

And here is the script to find these programs:

#!/bin/bash for name in /sbin/* /usr/sbin/* /bin/* /usr/bin/* do len=${#name} # len=3 => 1:2 0:1, 2:1 0:2 # len=4 => 1:3 0:1, 2:2 0:2, 3:1 0:3 for n in $(seq 1 $((len-1))) do init=${name:n:len-n} rest=${name:0:n} # echo $init$rest which /usr/bin/$init$rest 2>/dev/null >/dev/null && echo $name $init$rest $n done done 

[ is not found, but would be an interesting corner case too.

###sh, bash

cc cc: no input files 

cc rotated is cc again, but it is not very friendly if called so naked.

dh dh: cannot read debian/control: No such file or directory hd 

dh debhelper isn't very cooperative too, while hexdump just waits for input.

gs sg 

Ghostscript starts interactive mode, while switch group shows a usage message - a valid solution here, imho, too.

And here is the script to find candidates for such programs:

#!/bin/bash for name in /sbin/* /usr/sbin/* /bin/* /usr/bin/* do len=${#name} # len=3 => 1:2 0:1, 2:1 0:2 # len=4 => 1:3 0:1, 2:2 0:2, 3:1 0:3 for n in $(seq 1 $((len-1))) do init=${name:n:len-n} rest=${name:0:n} # echo $init$rest which /usr/bin/$init$rest 2>/dev/null >/dev/null && echo $name $init$rest $n done done 

If finds longer sequences too, like (arj, jar) or (luatex, texlua) which aren't valid after every shift, but only after some certain shifts, which I misread in the beginning, but there are few, so it is easy to filter them out by hand.