hom@houxm.UUCP (H.MORRIS) (04/12/85)
While on the topic of "echo", it is remarkably hard to have a background process output just a bell character with no carriage return (to signal that it is done, say, while I am in a vi session). I had been using a 'C' routine for this purpose, and finally discovered that I could say: echo "^G\c" only to find out it does not work with UCB 4.2. I use this in a package which is shipped to various machines and would like to have one less thing requiring compilation.
dave@uwvax.UUCP (Dave Cohrs) (04/13/85)
> I had been using a > 'C' routine for this purpose, and finally discovered that I could say: > echo "^G\c" > only to find out it does not work with UCB 4.2. With the 4.2BSD csh, the command 'echo -n ^G' works just fine. This is also the behavior of the 4.2 /bin/echo. The other version works on Sys[35] and version 7 (I think, it's been a while). -- dave cohrs ...!{allegra,harvard,ihnp4,seismo}!uwvax!dave dave@wisc-limburger.arpa (bug? what bug? that's a feature!)
ed@mtxinu.UUCP (Ed Gould) (04/14/85)
> ... and finally discovered that I could say: > echo "^G\c" > only to find out it does not work with UCB 4.2. Sure enuf. Years ago, in csh's infancy, some nameless author decided that the syntax echo -n ... was preferable. Since echo was a builtin to csh, it was possible for a time (under PDP-11 V7) to get the \c syntax from /bin/echo. That no longer works, either. /bin/echo is now a duplicate if csh's internal echo. -- Ed Gould mt Xinu, 739 Allston Way, Berkeley, CA 94710 USA {ucbvax,decvax}!mtxinu!ed +1 415 644 0146
long@ittvax.UUCP (H. Morrow Long [Systems Center]) (04/16/85)
> While on the topic of "echo", it is remarkably hard to have a background > process output just a bell character with no carriage return (to signal > that it is done, say, while I am in a vi session). I had been using a > 'C' routine for this purpose, and finally discovered that I could say: > echo "^G\c" > only to find out it does not work with UCB 4.2. For a good time read the story of echo in Kernighan and Pike's the Unix Programming Environment. The following program will work under 4.2bsd. #! /bin/sh # # Ring bell continuously, frequency varies with load average. # To be really irritating to other users redirect the output # to their terminals, i.e. 'annoy > /dev/ttyi4 &'. # while true do echo -n "" done -- H. Morrow Long ITT-ATC Systems Center, 1 Research Drive Shelton, CT 06484 Phone #: (203)-929-7341 x. 634 path = {allegra bunker ctcgrafx dcdvaxb dcdwest ucbvax!decvax duke eosp1 ittral lbl-csam milford mit-eddie psuvax1 purdue qubix qumix research sii supai tmmnet twg uf-cgrl wxlvax yale}!ittvax!long
mac@tesla.UUCP (Michael Mc Namara) (04/19/85)
In article <171@uwvax.UUCP> dave@uwvax.UUCP (Dave Cohrs) writes: >> I had been using a >> 'C' routine for this purpose, and finally discovered that I could say: >> echo "^G\c" >> only to find out it does not work with UCB 4.2. > >With the 4.2BSD csh, the command 'echo -n ^G' works just fine. This is also >the behavior of the 4.2 /bin/echo. The other version works on Sys[35] and >version 7 (I think, it's been a while). >-- >dave cohrs >...!{allegra,harvard,ihnp4,seismo}!uwvax!dave >dave@wisc-limburger.arpa > > (bug? what bug? that's a feature!) We're beta testing a U**X 4.2/SYS5 on a Data General, and while echo "kalshf\c" works in sh, the same thing in csh produces % echo "kalshf\c" kalshf\c % Oh well, I guess that's why they've got us testing it; who else but a net reader would care? -mac@tesla.arpa ____________________________________________________________________________ On a clear disk you can see forever | ----------------------------------------------------------------------------
smithrd@rtp47.UUCP (Randy D. Smith) (04/25/85)
>>> echo "^G\c" >>> only to find out it does not work with UCB 4.2. >> >>With the 4.2BSD csh, the command 'echo -n ^G' works just fine... > > We're beta testing a U**X 4.2/SYS5 on a Data General, and while >echo "kalshf\c" works in sh, the same thing in csh produces... > Oh well, I guess that's why they've got us testing it; who else but >a net reader would care? -mac@tesla.arpa > >____________________________________________________________________________ >On a clear disk you can see forever | >---------------------------------------------------------------------------- `echo "^G\c"` behaves as expected when interpreted by the Bourne shell, while `echo -n "^G"` behaves as expected when interpreted by the csh. "U**X 4.2/SYS5 on a Data General" (a.k.a. DG/UX) gives you the best of both worlds, with both shells, each with the built-in command "echo" behaving as expected. To get Bourne shell behavior from the csh, just use /bin/echo; to get csh behavior from the Bourne shell, exec off a csh to handle the echo. (By the way, the quote given in Knuth is "On a clear disk you can seeK forever". Makes a little more sense that way.) ^ [Please note that the preceding announcement reflects the viewpoint of myself and myself alone. My signature includes my employer's name for information/identification purposes only. This posting should NOT be interpreted as a positional statement by any corporations either living, dead, or otherwise ...] -- Randy D. Smith Data General, Research Triangle Park, NC {the known world}!mcnc!rti-sel!rtp47!smithrd