I need help from expert on this. How can I add @ at the first byte of the line after found matching pattern. For example as below : Input: Output: Answer You may execute the following sed script on the file: sed -n ‘/TESTING/{p;n;s/^/@/;};p;’ file -n – don’t print output on default /TE…
How to add Chromedriver to PATH in linux?
Trying to use Selenium with Chrome in a python script. I get the following error: I know the location of the chromedriver executable. How do I add it to the PATH? thank you Answer You can specify the absolute path to your chrome driver in your script as such: Or you can add the path to your webdriver in the
Count of files between 2 size in Linux
Hi I want to find count of file between 2 size (for example 1k and 2k) in linux, I found that the code return the count of exact size in a directory and it work fine: could anyone help me how I do find between 2 size? And is it possible that I find the count of Hiden file via
How to create a system-wide file lock?
I am trying to have a number of independent processes coordinate their writing to file using a system-wide lock (see here: Concurrent file accesses from different scripts python) The lock needs to span the whole system, because the processes are spawn independently and at different times. Here: System-wide mu…
Cron format for specific date and time, running once a year only
I have to schedule the cron to run at specified time. I have the command like below. But I could not understand how to run only once in a year at a specified date and time. My question is: what should the value for 5th field (Day of the Week) be? Time/date: Jan 2nd 06:30 AM – only once in
extracting a n element from a list with dolist on lisp
I am trying to create a function where it takes a list of letters as parameter and a single letter as a parameter. I want to remove the single letter from the list. so if I call the function with (extract-all ‘n ‘(i n t e l l)), I want it to return i t e l l with the
How to clear CPU cached owned by a process in Linux x86
I want to get the kernel APIs which can be used to flush/clear the CPU cache owned by a specific process. Answer There’s no such thing as “CPU cache owned by a process”. The CPU / memory controller manages the cache, not the OS. On some CPU architectures (I don’t know!) it might be pos…
Connect to Vehicle Using Telemetry on Linux
I am having problems with connection to vehicle. First, I could not connect to the vehicle even with USB (I used “/dev/ttyUSB0” connection string and got an error). Later I got it working with connection string ‘/dev/serial/by-id/usb-3D_Robotics_PX4_FMU_v2.x_0-if00’ and was able to sen…
How to delete lines that match elements from another file
I am in the process of learning Perl and I am trying to figure out how to do this task. I have a folder with a bunch of text files and I have a file ions_solvents_cofactors that contains bunch of three letters list. I wrote a script that opens and reads each file in a folder and should delete those
Change some field separators in awk
I have a input file 1.txt and I want an output file: out.txt I want to replace the first two ‘:’ in 1.txt with ‘||o||’, but with the script I am using But it is not giving the expected output. Any help would be highly appreciated. Answer Following sed may also help you in same. Explana…