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If you are a coder like me we tend to discover after we have made a script that we need to change something on multiple lines. Recently I have a script whereby added a “log_message” function which would echo a phrase. However, I wanted to append a double parenthesis after the last character in the
Read MoreThere are times when you may unintentionally delete a file which is being written to. When this occurs it will leave an Open Filehandle. In Linux open filehandles may be viewed via the ‘lsof’ command. # lsof +L1 In the following example here was the situation. $ lsof +L1 COMMAND PID USER FD TYPE DEVICE
Read MorePart of my ‘day job’ is trolling thru source code when looking for answers. My preferred mechanism, other than a recursive grep, is to use cscope Cscope is a useful tool for searching a source code tree after you build a list of files to search The Problem However, in this conundrum, when I would
Read MoreEncountered a fun riddle recently whereby on a Fedora 34 system I needed to locate all ethernet interfaces on a system that are obtaining a DHCP address, then after the first reboot create a static IP address. I am a big fan of looking thru the Linux pseudo filesystem in /sys In this instance I
Read MoreThere are times when you need to fully download an RPM and all of its dependencies. However, If you have already downloaded the RPM re-downloading the RPM and all its dependencies can be very difficult. I have found the following is a way to use an alternate installation ‘root’ directory so that you can ensure
Read MoreGot stuck earlier in an interesting regex mystery and I command-line FU’d an AWK Solution. PROBLEM I want to strip out all spaces and/or special characters from an IP address PROCESS I know how to validate an IP address no problem.. Good IPO Bad IP However.. What if am gathering user input via script and
Read MoreOften you are looking for a keyword within a log file but you need to print out X lines BEFORE the first match of a string, THEN exit the search. There are many ways to skin a cat, and here are a few ways. EXAMPLE 1: In the following I am looking for 7 lines
Read MoreThere are situations where you may be working on Linux based system, and telnet, ncat or nmap does not exist. In Linux, you can route a test thru the protocol, destination IP address, and destination port using the “/dev” linux ‘pseudo device’ The ‘telnet’ command we are all familiar with is essentially a wrapper for
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