I use tool called byzanz to record my screen and create gif files.
This is the way I use it:
byzanz-record -d 55 --delay=2 -x 0 -y 0 -w 3940 -h 950 desktop-animation.gif
However, often I can't tell in advance how long the recording will be so it ends up with awkward moments at the end or prematurely ending the recording. Is there a way how to tell byzanz to stop its job, perhaps by sending a signal to it with kill or something?
There seems to be an option that could achieve that :
http://manpages.ubuntu.com/manpages/zesty/man1/byzanz-record.1.html
-e, --exec=COMMAND
Instead of specifying the duration of the animation, execute the
given COMMAND and record until the command exits. This is useful
both for benchmarking and to use more complex ways to stop the
recording, like writing scripts that listen on dbus.
However, in my package manager with the latest byzanz (fedora), --exec doesn't exist.
I think with that option, you could do :
byzanz-record --exec 'sleep 1000000' --delay=2 -x 0 -y 0 -w 3940 -h 950 desktop-animation.gif
and when you want to stop the recording, do : killall sleep
Sidenote: I have opened an issue on redhat bugzilla tracker to update their byzanz-record version : https://bugzilla.redhat.com/show_bug.cgi?id=1531055
Related
I run benchmarks with apache bench on a web service. I know that 1-2 requests from the test will be timeouted during measurement (it's a web framework issue). And when timeout occurs ab quits with the message apr_pollset_poll: The timeout specified has expired (70007) and does not show results. I want to get measurement results ignoring these timeouted tests (or count them too, but just use timeout value as response time). Is it possible with ab?
EDIT: The command I use is
ab -n 1000 -c 10 http://localhost:80
I looked into ab source and from what I saw it's impossible to ignore these errors. Maybe there is a fork which implements such feature?
The default timeout is 30 seconds. You can change this with -s:
ab -s 9999 -n 1000 -c 10 http://localhost:80
I'm running GNU - Screen (4.03.01) so I can have multiple terminals in one, and I'm looking for a good way to display live stats of my memory, so as I do things like compiling, testing programs, etc... I can see how much resources I have left.
I know there is "TOP" the performance monitor... and other similar programs, but I'm not looking for the entire active process list etc... I just want a snapshot of my memory stats that updates for example every 3-5 seconds.
I really appreciate anyone taking the time to help me with this, so thank you!
(for visualization purposes)
Screenshot:
You can use the combination of watch which repeats the specified program and displays its output and free which shows current memory usage
watch free -m
free --help
Usage:
free [options]
Options:
-b, --bytes show output in bytes
-k, --kilo show output in kilobytes
-m, --mega show output in megabytes
-g, --giga show output in gigabytes
--tera show output in terabytes
-h, --human show human-readable output
--si use powers of 1000 not 1024
-l, --lohi show detailed low and high memory statistics
-o, --old use old format (without -/+buffers/cache line)
-t, --total show total for RAM + swap
-s N, --seconds N repeat printing every N seconds
-c N, --count N repeat printing N times, then exit
--help display this help and exit
-V, --version output version information and exit
For more details see free(1).
watch --help
Usage:
watch [options] command
Options:
-b, --beep beep if command has a non-zero exit
-c, --color interpret ANSI color sequences
-d, --differences[=]
highlight changes between updates
-e, --errexit exit if command has a non-zero exit
-g, --chgexit exit when output from command changes
-n, --interval seconds to wait between updates
-p, --precise attempt run command in precise intervals
-t, --no-title turn off header
-x, --exec pass command to exec instead of "sh -c"
-h, --help display this help and exit
-v, --version output version information and exit
You could use valgrind tool Massif, I haven't tried it, but it seems to be what you are looking for.
To use massif, install valgrind then run:
valgrind --tool=massif program argument1 argument2 ...
another fast solution is script like this
while true; do
free -m
# any command for CPU stats - i didn't understand - what you really want to see, please clarify - just % of CPU usage ?
# i think this command should help you.
ps -A -o pcpu | tail -n+2 | paste -sd+ | bc
done
The other thing you can do is use htop. It displays memory usage, CPU usage per core and shows resources used by each process. Really neat but maybe not that detailed as the rest of the answers.
I want to make a shell script that keeps running to check if my two light weight web servers are still running, and restart them if one is not.
I can use the the command pgrep -f thin to get an array (?) of pids of my server called thin.
When this returned array has a count of zero I want to run a command which starts both servers:
cd [path_to_app] && bundle exec thin -C app_config.yml start
pgrep -f thin returns all the pids of the servers that are running. For example:
2354223425
I am new to shell scripting and don't know how to store the results of pgrep-f thin in an array. E.g.,
#!/bin/sh
while true
do
arr=$(pgrep -f thin) # /edited and now THIS WORKS!
#Then I want to check the length of the array and when it is empty run the above
#command, e.g.,
if [ ${#arr[#]} == 0 ]; then
cd [path_to_app] && bundle exec thin -C app_config.yml start
fi
#wait a bit before checking again
sleep 30
done
The first problem I have is that I cannot store the pgrep values in an array, and I am not sure if I can check against zero values. After that I am not sure if there are problems with the other code. I hope someone can help me!
You forgot to execute the command:
arr=($(pgrep -f thin))
[...] when it is empty
If you only check for emptyness, you can directly use the exit status of grep.
-q, --quiet, --silent
Quiet; do not write anything to standard output.
Exit immediately with zero status
if any match is found, even if an error was detected.
Solution at end of this post.
By default the time is set to one second, and under the usual iputils version of ping there is an option to reduce this number with the -i switch. I need to ping faster, as I have 120 pings in a certain test that needs to be run many times.
I tried modifying the source of ping.c from the busybox source but I don't know much about compiling and I get the error "could not be found libbb.h" and I couldn't find anyone else with a similar error on busybox.
Does anyone know of a way for me to ping faster than 1 per second, I am hoping to go down to 0.1 or 0.05 seconds if at all possible.
Thanks in advance
Solution
In case anyone comes looking for an answer, the solution I came up with was much better. If you write a script to ping with the -c 1 flag, and count the failures yourself you can ping much faster.
Example:
fails=0
for i in `seq 1 20`
do
x=`ping -c 1 192.168.1.1 | grep received | cut -d' ' -f4`
if [ x -eq 0 ]
then
fails=$(($fails+1))
fi
done
echo $fails fails
done
You are correct in that you have to modify the ping.c file. As you have determined, BusyBox ping does not support the -i switch.
What platform are you building this for? A PC, an embedded system?
Option 1:
Modify ping.c from BusyBox and recompile BusyBox. To do this, you would use 'make' in the root of the BusyBox project.
user#linux:~/busybox-1.19.2$ make
Option 2:
It might be easier and more simplistic to leave BusyBox alone and get ping.c from another archive such as iputils. This supports the -i switch and goes as low as 0.2 seconds. To compile ping.c:
user#linux:~/iputils-s20101006$ make ping
From what was suggested here, I am trying to pipe the output from sqlcmd to 7zip so that I can save disk space when dumping a 200GB database. I have tried the following:
> sqlcmd -S <DBNAME> -Q "SELECT * FROM ..." | .\7za.exe a -si <FILENAME>
This does not seem to be working even when I leave the system for a whole day. However, the following works:
> sqlcmd -S <DBNAME> -Q "SELECT TOP 100 * FROM ..." | .\7za.exe a -si <FILENAME>
and even this one:
> sqlcmd -S <DBNAME> -Q "SELECT * FROM ..."
When I remove the pipe symbol, I can see the results and can even redirect it to a file within finishes in 7 hours.
I am not sure what is going on with piping large amount of output but what I could understand up until this point is that 7zip seems to be waiting to consume the whole input before it creates an archive file (because I don't really see a file being created to begin with) so I am not sure if it is actually performing on-the-fly compression. So I tried gzip and here's my experience:
> echo "Test" | .\gzip.exe > test.gz
> .\gzip.exe test.gz
gzip: test.gz: not in gzip format
I am not sure I am doing this the right way. Any suggestions?
Oh boy! It was PowerShell all along! I have no idea why this is happening at least with gzip. Gzip kept complaining that the input was not in gzip format. I switched over to the normal command prompt and everything started working.
I did observe this before. Looks like | and > have a slightly different functionality in PowerShell and Command prompt. Not sure what exactly it is but if someone knows about it, please add in here.