Hi,
I have a script as follows:
#!/bin/sh
nohup ./my_program >& /dev/null &
However, i get a "Generated or received a file descriptor number that is not valid" whenever I run it.
running the command up in prompt is ok though.
if i change the first line to #!/bin/csh
i get a then:... (4 Replies)
Please help urgently.
I need to setup up some sort of service on a solaris server on a port.
I dont need it do anything special, anything that is sent to this port from an external server should be dump to /dev/null or a flat file..
Can you help urgently? (1 Reply)
Hi, Anyone can help
My solaris 8 system has the following
/dev/null , /dev/tty and /dev/console
All permission are lrwxrwxrwx
Can this be change to a non-world write ??
any impact ?? (12 Replies)
Hi,
Excuse my ignorance here - I'm a networks man and my knowledge of all things unix is somewhat limited.
We have a very large file (/var/tmp/mond.log) that we need to zero - does the "cat /dev/null > /var/tmp/mond.log" command achieve this? (4 Replies)
Hello,
I am working on a script to measure the read performance of a busybox environment. The logical choice is to use a command line like:
(time cp * /dev/null) 2> /tmp/howlong.txt
Ah, the rub is cp or /dev/null will only accept a single file at a time.
The result in the txt file is and... (1 Reply)
I stumbled across a somewhat strange behavior of tar and find no explanation for it: i was testing a DVD for read errors and thought to simply tar the content and direct the output to /dev/null:
tar -cvf - /my/mountpoint/*ts > /dev/null
This way i expected the system to read the complete... (4 Replies)
How are these two different? They both prevent output and error from being displayed. I don't see the use of the "&"
echo "hello" > /dev/null 2>&1
echo "hello" > /dev/null 2>1 (3 Replies)
Hi Guru's,
I am trying to test the network speed or load by this command.
but getting error " Not Connected ". Could you guys please help.
ftp> put "|dd if=/dev/zero bs=8k count=1000000" /dev/null
Not connected.
Please use
code tags! (9 Replies)
I apologize if this question has been answered else where or is too elementary.
I ran across a KSH script (long unimportant story) that does this:
if ; then
CAS_SRC_LOG="/var/log/cas_src.log 2>&1"
else
CAS_SRC_LOG="/dev/null 2>&1"
fithen does this:
/usr/bin/echo "heartbeat:... (5 Replies)
I'm using an text-to-speech synthesis in a script, and I need to redirect it's output to /dev/null
how can I do that ? And how to redirect the stream to his normal output then (sound card ) ?
thankx (2 Replies)
Discussion started by: firelink
2 Replies
LEARN ABOUT LINUX
unbuffer
UNBUFFER(1) General Commands Manual UNBUFFER(1)NAME
unbuffer - unbuffer output
SYNOPSIS
unbuffer program [ args ]
INTRODUCTION
unbuffer disables the output buffering that occurs when program output is redirected from non-interactive programs. For example, suppose
you are watching the output from a fifo by running it through od and then more.
od -c /tmp/fifo | more
You will not see anything until a full page of output has been produced.
You can disable this automatic buffering as follows:
unbuffer od -c /tmp/fifo | more
Normally, unbuffer does not read from stdin. This simplifies use of unbuffer in some situations. To use unbuffer in a pipeline, use the
-p flag. Example:
process1 | unbuffer -p process2 | process3
CAVEATS
unbuffer -p may appear to work incorrectly if a process feeding input to unbuffer exits. Consider:
process1 | unbuffer -p process2 | process3
If process1 exits, process2 may not yet have finished. It is impossible for unbuffer to know long to wait for process2 and process2 may
not ever finish, for example, if it is a filter. For expediency, unbuffer simply exits when it encounters an EOF from either its input or
process2.
In order to have a version of unbuffer that worked in all situations, an oracle would be necessary. If you want an application-specific
solution, workarounds or hand-coded Expect may be more suitable. For example, the following example shows how to allow grep to finish pro-
cessing when the cat before it finishes first. Using cat to feed grep would never require unbuffer in real life. It is merely a place-
holder for some imaginary process that may or may not finish. Similarly, the final cat at the end of the pipeline is also a placeholder
for another process.
$ cat /tmp/abcdef.log | grep abc | cat
abcdef
xxxabc defxxx
$ cat /tmp/abcdef.log | unbuffer grep abc | cat
$ (cat /tmp/abcdef.log ; sleep 1) | unbuffer grep abc | cat
abcdef
xxxabc defxxx
$
BUGS
The man page is longer than the program.
SEE ALSO
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive Programs" by Don Libes, O'Reilly and Associates, January 1995.
AUTHOR
Don Libes, National Institute of Standards and Technology
1 June 1994 UNBUFFER(1)