Hallo
I want write a sh script but I have some troubles!
How can I write the Return value to a variable? I need an egrep command with the option -c, how many times it give the pattern. This return value shold be written in a variable.
Could you help me? (1 Reply)
I have an execution in my shell script when run return a xxx.log file
how wil i be able to get the name of the file and read it then test the string written in the file by the programs...
Anyone can help me please...
Am new to shell programming......
Lutchumaya (1 Reply)
I want to know if there is any documentation or any type of information that can give a list of all of the return codes that can be seen in the /var/cron/log. I have seen a couple in my log file. Example: rc=1 and rc=64. (2 Replies)
Hi All,
Can anyone please let me know the syntax / how to pick up the Return Code ( RC) from the mailx command and return it to SAS uisng 'system()' function and '${?}'.
I am in a process to send the mail automatically with an attachment to bulk users. I have used 'Mailx' and 'Unencode'... (0 Replies)
Folks -
Firstly, I do apologize that my first post here is a question. I am quite familiar with UNIX since our application is running on it. We are trying to automate a few things on our end and I am challenged with a task in hand that requires UNIX scripting. I am totally a newbie in UNIX... (4 Replies)
ls xx > yy.log
echo $? can get the return value of "ls xx"
but if I use
ls xx |tee -a yy.log
I can't get the return value of "ls xx", and I get the return value of the whole cmd "ls xx |tee -a yy.log", it is always "0"
my question is how could I get the return value of "ls xx"... (1 Reply)
Not sure where the problem is. I can run the script without any issue using the following command.
. /opt/app/scripts/cdc_migration.sh
But it fails with the below error when I try it this way
/opt/app/scripts/cdc_migration.sh
/opt/app/scripts/cdc_migration.sh: line 65: return: can only... (1 Reply)
Discussion started by: svajhala
1 Replies
LEARN ABOUT CENTOS
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)