a) You are directing standard out to 'nothing' to direct errors, you would use
2>/dev/null
b) I have found that the error redirect is command specific. Thus you are only, in your example, dealing with output from the 2nd command. Off the top of my head, I would think something like:
I need to suppress the output to the screen. I am appending to a file so do not need the output on the screen in the CLI environment.
eg.
cat $HOME/somefile >> $HOME/anotherfile
I am doing this a number of times with SQL output files so I can look at the finished file not on the screen in the... (3 Replies)
Hi,
One of our application is producing log files. But if we open the log file in vi or less or view mode, it shows all the special characters in it. The 'cat' shows correctly but it shows only last page. If I do 'cat' <file_name> | more, then again it shows special characters.
... (1 Reply)
I am using this command
find . -type f -mmin "+$t" > holder
Unfortunatley that is also printing files that begin with a period. Such as .bash_history.
What can I do to supress files that begin with a period? (1 Reply)
Hi All
this is a simple script
#! /bin/bash
FileCnt=`ls -lrt $DIR/* | wc -l`
echo $FileCnt
how could i escape the error msg if there are no files in $DIR
ls: /home/sayantan/test/files/cnt/*: No such file or directory
0
Looking forward for a quick reply
Regards, Newbie (2 Replies)
Hi
I have a script which connects to oracle using sqlplus
if ! check_sqlplus "$ORACLE_SID" ; then
echo "Unable to use sqlplus for sid $ORACLE_SID"
return 1
else
echo "attempting to connect to database"
echo $ORACLE_HOME
echo $ORACLE_SID
echo "Status before entering... (2 Replies)
Hi,
I am trying to run a script using awk and sed a few times.
The script itself seems to work fine but in a final awk statement it throws up a warning:
awk: warning: escape sequence `\.' treated as plain `.'
script:
... (3 Replies)
Hi Team ,
I want supress the meaning of * while passing it as parameter.
I have file which contains file format and destination directory.
let say abc* |/home/xyz
I had function which will read these values and pass it to another function.
Code looks like below
func1 ()
{... (6 Replies)
Hi,
I was looking for a simple code to suppress the text between 2 characters. the characters can be of same kind like "*" or "(" and ")". The number of characters are not consistent and could vary.
How can I suppress the text between 2 characters?
Example:
Input : Hello (Within Bracket)... (8 Replies)
I am running the ETL job to passing the database username,pssswd positional arguments to shell script (bash) and how can we suppress/hide the password from ps command. (2 Replies)
Hello,
I know this isn't exactly a shell script question but I'm not sure where else to post it.
I am running a java program out of a shell script. There are times when I get an error like,
"java.lang.ArrayIndexOutOfBoundsException: 22
at blah, blah
at blah, blah
... (3 Replies)
Discussion started by: LMHmedchem
3 Replies
LEARN ABOUT CENTOS
trace-cmd
TRACE-CMD(1)TRACE-CMD(1)NAME
trace-cmd - interacts with Ftrace Linux kernel internal tracer
SYNOPSIS
trace-cmd COMMAND [OPTIONS]
DESCRIPTION
The trace-cmd(1) command interacts with the Ftrace tracer that is built inside the Linux kernel. It interfaces with the Ftrace specific
files found in the debugfs file system under the tracing directory. A COMMAND must be specified to tell trace-cmd what to do.
COMMANDS
record - record a live trace and write a trace.dat file to the
local disk or to the network.
report - reads a trace.dat file and converts the binary data to a
ASCII text readable format.
hist - show a histogram of the events.
options - list the plugin options that are available to *report*
start - start the tracing without recording to a trace.dat file.
stop - stop tracing (only disables recording, overhead of tracer
is still in effect)
extract - extract the data from the kernel buffer and create a trace.dat
file.
reset - disables all tracing and gives back the system performance.
(clears all data from the kernel buffers)
split - splits a trace.dat file into smaller files.
list - list the available plugins or events that can be recorded.
listen - open up a port to listen for remote tracing connections.
restore - restore the data files of a crashed run of trace-cmd record
stack - run and display the stack tracer
check-events - parse format strings for all trace events and return
whether all formats are parseable
OPTIONS -h, --help
Display the help text.
Other options see the man page for the corresponding command.
SEE ALSO trace-cmd-record(1), trace-cmd-report(1), trace-cmd-hist(1), trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-extract(1),
trace-cmd-reset(1), trace-cmd-restore(1), trace-cmd-stack(1), trace-cmd-split(1), trace-cmd-list(1), trace-cmd-listen(1), trace-cmd.dat(5),
trace-cmd-check-events(1)AUTHOR
Written by Steven Rostedt, <rostedt@goodmis.org[1]>
RESOURCES
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
COPYING
Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).
NOTES
1. rostedt@goodmis.org
mailto:rostedt@goodmis.org
06/11/2014 TRACE-CMD(1)