02-09-2009
Non-blocking pipe
Hello,
Would this be an acceptable way of creating a non-blocking pipe.
Basically I want to create kind of a server client arch.
This code would be in the server, and I don't want to have to wait for
clients to read before moving on to the next client. One problem I
can see is if a client leaves/dies and never reads from the pipe(but I
could have some trap/cleanup stuff in the clients for that).
# assigning fd 3 to the pipe
echo "exec 3>myfifo && echo 'a' >&3 && echo 'b' >&3 && echo 'c' >&3 &&
exec 3>&-" | at now
Chris.
Last edited by Neo; 02-09-2009 at 05:25 PM..
Reason: removed self promoting link of new member
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echo(1) General Commands Manual echo(1)
NAME
echo - echo (print) arguments
SYNOPSIS
[arg] ...
DESCRIPTION
writes its arguments separated by blanks and terminated by a new-line on the standard output. It also understands C-like escape conven-
tions; beware of conflicts with the shell's use of
write an alert character
backspace
print line without appending a new-line
form-feed
new-line
carriage return
tab
vertical tab
backslash
the 8-bit character whose
ASCII code is the 1-, 2-, 3- or 4-digit octal number n, whose first character must be a zero.
write an 8-bit value that is the zero-, one-, two- or three-digit octal number
num
is useful for producing diagnostics in command files and for sending known data into a pipe.
Notes
Berkeley differs from this implementation. The former does not implement the backslash escapes. However, the semantics of the escape can
be obtained by using the option. The echo command implemented as a built-in function of follows the Berkeley semantics (see csh(1)).
EXTERNAL INFLUENCES
Environment Variables
determines the interpretation of arg as single and/or multi-byte characters.
If is not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty vari-
able. If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of If any internationalization
variable contains an invalid setting, behaves as if all internationalization variables are set to "C". See environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
AUTHOR
was developed by OSF and HP.
SEE ALSO
sh(1).
BUGS
No characters are printed after the first This is not normally a problem.
STANDARDS CONFORMANCE
echo(1)