Re: [TUHS] sh: cmd | >file

markus schnalke wrote in &lt;1inMKv-0Km-00(a)marmaro.de&gt;: |Hoi, Morsche. |in a computer forum I came across a very long command line, |including `xargs' and `sh -c'. Anyways, throughout the thread |it was modified several times, when accidently a pipe symbol |appeared between the command and the output redirection. The |command line did nothing; it ran successful. I was confused, |because I expected to see a syntax error in case of |``cmd|>file''. This made me wonder ... | | |With help of Sven Mascheck, I was able to clear my understanding. |The POSIX shell grammer provided the answer: ... |A redirection is a (full) simple_command ... and because |``simple_command | simple_command'' is allowed, so is |``io_file | io_file''. This can lead to such strange (but |valid) command lines like: | | <a | >b |>b | <a | |Sven liked this one: | |:|>: | |Here some further fun variants: | |:|:>: | | <:|:>: | |They would provide nice puzzles. ;-) ... |- Syntax ok in these shells: | |SVR2 sh (Ultrix), SVR4 sh (Heirloom) Be aware of spurious :> errors in Heirloom shell, and maybe its origin (never had those). It is why the unit test of my little web site builder thing has been switched to "printf '' > FILE". |ksh93 |bash-1.05, bash-aktuell |pdksh-5.2.14 |ash-0.4.26, dash-0.5.6.1 |posh-0.3.7, posh-0.12.3 |mksh-R24, mksh-R52b |yash-2.29 |zsh-3.0.8, zsh-4.3.17 | |- Exception to the rule: | |7thEd sh: | |    # pwd|>>file |    # echo $? |    141 | |On first sight ok, but with a silent error ... SIGPIPE (128+13). | |I'd be interested in any stories and information around this |topic. | |What about 7thEd sh? Beware of bugs in the above code; I have only proved it correct, not tried it. |meillo --End of &lt;1inMKv-0Km-00(a)marmaro.de&gt; --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt)