While running a bash shell script which contains this command:
iperf -c $server_ip -p $iperf_port -t $iperf_duration >> outputfile
the output is many times displayed on console rather than getting appended in the outputfile. Any solutions for same? Am I doing anything wrong?
I am using Ubuntu 12.04
I'm not familiar with iperf, but presumably it's writing some or all of its output to standard-error rather than to standard-output. To merge standard-error with standard-output and send them both to your file, you can add 2>&1 to the end:
iperf -c $server_ip -p $iperf_port -t $iperf_duration >> outputfile 2>&1
Related
So i'm trying to take the line-by-line output of a program, then send it to a file if it matches "CPU", also I want every line to go to the screen.
This command works but only after quitting the script with ^C:
cpuminer-multi/cpuminer -u user -p pass -a sha256d -o stratum+tcp://stratum.pool.com:3333 -t cputhreads | tee >(grep "CPU" >> cpu.txt);
but then if I copy and paste it into a bash script "start.sh"
#!/bin/bash
cpuminer-multi/cpuminer -u user -p pass -a sha256d -o stratum+tcp://stratum.pool.com:3333 -t cputhreads | tee >(grep "CPU" >> cpu.txt);
and run it from bash as "./start.sh", it populates cpu.txt with nothing, even after quitting with ^C
So my questions are
A: Why does it only populate the cpu.txt file after ^C?
B: Why does it work as a plain bash command, but not in a script?
English is not my native language, please accept my apologies for any language issues.
I want to execute a script (bash / sh) through CRON, which will perform various maintenance actions, including backup. This script will execute other scripts, one for each function. And I want the entirety of what is printed to be saved in a separate file for each script executed.
The problem is that each of these other scripts executes commands like "duplicity", "certbot", "maldet", among others. The "ECHO" commands in each script are printed in the file, but the outputs of the "duplicity", "certbot" and "maldet" commands do not!
I want to avoid having to put "| tee --append" or another command on each line. But even doing this on each line, the "subscripts" do not save in the log file. That is, ideally in the parent script, you could specify in which file each script prints.
Does not work:
sudo bash /duplicityscript > /path/log
or
sudo bash /duplicityscript >> /path/log
sudo bash /duplicityscript | sudo tee –append /path/log > /dev/null
or
sudo bash /duplicityscript | sudo tee –append /path/log
Using exec (like this):
exec > >(tee -i /path/log)
sudo bash /duplicityscript
exec > >(tee -i /dev/null)`
Example:
./maincron:
sudo ./duplicityscript > /myduplicity.log
sudo ./maldetscript > /mymaldet.log
sudo ./certbotscript > /mycertbot.log
./duplicityscript:
echo "Exporting Mysql/MariaDB..."
{dump command}
echo "Exporting postgres..."
{dump command}
echo "Start duplicity data backup to server 1..."
{duplicity command}
echo "Start duplicity data backup to server 2..."
{duplicity command}
In the log file, this will print:
Exporting Mysql/MariaDB...
Exporting postgres...
Start duplicity data backup to server 1...
Start duplicity data backup to server 2...
In the example above, the "ECHO" commands in each script will be saved in the log file, but the output of the duplicity and dump commands will be printed on the screen and not on the log file.
I made a googlada, I even saw this topic, but I could not adapt it to my necessities.
There is no problem in that the output is also printed on the screen, as long as it is in its entirety, printed on the file.
try 2>&1 at the end of the line, it should help. Or run the script in sh -x mode to see what is causing the issue.
Hope this helps
Looking over the Dokku source code, I noticed two uses of pipe and redirect that I am not familiar with.
One is: cat | command
Example: id=$(cat | docker run -i -a stdin progrium/buildstep /bin/bash -c "mkdir -p /app && tar -xC /app")
The other is cat > file
Example: id=$(cat "$HOME/$APP/ENV" | docker run -i -a stdin $IMAGE /bin/bash -c "mkdir -p /app/.profile.d && cat > /app/.profile.d/app-env.sh")
What is the use of pipe and redirect in the two cases?
Normally, both usages are completely useless.
cat without arguments reads from stdin, and writes to stdout.
cat | command is equivalent with command.
&& cat >file is equivalent with >file, assuming the previous command processed the stdin input.
Looking at it more closely, the sole purpose of that cat command in the second example is to read from stdin. Without it, you would redirect the output of mkdir to the file. So the command first makes sure the directory exists, then writes to the file whatever you feed to it through the stdin.
I'm attempting to write a bash script that uses nohup and passes errors to rsyslog.
I've tried this command with different variations of the log variable (see below) but can't get the output passed to anything but a std txt file. I can't get it to pipe.
nohup imageprocessor.sh > "$LOG" &
Is it possible to pipe nohup output or do I need a different command.
A couple of variations of log that I have tried
LOG="|/usr/bin/logger -t workspaceworker -p LOCAL5.info &2"
or
LOG="|logtosyslog.sh"
or
LOG="logtosyslog.sh"
A way in bash to redirect output to syslog is:
exec > >(logger -t myscript)
stdout is then sent to logger command
exec 2> >(logger -t myscript)
for stderr
Not directly. nohup will detach the child process, so piping the output of the nohup command isn't helpful. This is what you want:
nohup sh -c 'imageprocessor.sh | logger'
I'm trying to write a script that does
x =$ncore
numactrl -C $x ( time -p $exe ) > out.txt 2>&1
on the terminal ( time $ exe ) > out.txt 2>&1 worked as i wanted to (out.txt containing output of time and executable )
i'm using red hat 6.2 and time is not GNU version( i'm assuming from the fact that -a -o options don't work)
i want out.txt to have output from the executable and at the end have output from the time command.
the bash script is giving me problems with having ( so i used ( time -p $exe ) and now numactl sees ( as the executable.
is there a way to use numactl and time command together and have the output i want ?
If numactrl wants a command, but you want to use some shell features, just give it the shell as a command:
numactrl -C $x bash -c "( time -p $exe ) > out.txt 2>&1"
When you runtime -p $exe from a bash prompt or within a bash -c, you're using the bash builtin version of time. The one with the -o option is an external command, so to use it from bash you have to specify command time or /bin/time or /usr/bin/time.
If you run numactrl -C $x time ... then it probably runs the external command, so -o should work in that case, but if not then you always have the bash -c method.
Note that the output format is different between the various versions of time. The GNU coreutils version prints more information than the bash builtin version.