How to search history commands very effectively in bash shell command line?
How to search history commands very effectively in bash shell command line?
Just enter CTRL+r
The function of above is: (reverse-i-search)`’:
It is very fast and efficient.
How to search history commands very effectively in bash shell command line?
Just enter CTRL+r
The function of above is: (reverse-i-search)`’:
It is very fast and efficient.
I would like to know whether a function, say f1(), has already been defined in Bash. How should I do it? You can use the type -t to get a string of the type of the name: If the -t option is used, type prints a string which is one of alias, keyword, function, builtin,…
How to delete or get the number in the tail from a string in shell script (bash script)? Okay to call other tools. For example, from “/dev/sda8”, I want to get “/dev/sda” and “8” separately. This can be achieved by using sed as follows. To get the string after deleting the tailing numbers, we can…
Where to check the default Hadoop 2 (YARN) configuration values for: HDFS: hdfs-site.xml YARN: yarn-site.xml MapReduce: mapred-site.xml Default Hadoop 2 (YARN) configuration values for Hadoop 2.2.0 from Apache Hadoop website: HDFS: http://hadoop.apache.org/docs/r2.2.0/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml YARN: https://hadoop.apache.org/docs/r2.2.0/hadoop-yarn/hadoop-yarn-common/yarn-default.xml MapReduce: https://hadoop.apache.org/docs/r2.2.0/hadoop-mapreduce-client/hadoop-mapreduce-client-core/mapred-default.xml Read more: Good introductions to Hadoop 2.0 (YARN)? Hadoop Installation Tutorial (Hadoop 2.x) Hadoop Installation Tutorial (Hadoop 1.x) Hadoop…
Formatting code shortcuts in Eclipse. Shortcut: Ctrl + Shift + F No need to select the code. Read more: C++ cout formatting output Large-but-correctly-aligned-and-optimized code is faster than less-bytes-per-instruction/opcode-packed code How to get the assembly code for OCaml code generated by ocamlopt? Google Chrome keyboard and mouse shortcuts for Linux and Windows In Vim, are…
How to measure the execution time of a function, say f: ‘a -> ‘b in OCaml? This small OCaml function is handy: let time f = let t = Unix.gettimeofday () in let res = f () in Printf.printf “Execution time: %f secondsn” (Unix.gettimeofday () -. t); res ;; The gettimeofday returns a float representing…
With a list of servers, it is common that one or more are down or crash. Lots cluster management tools can detect the aliveness of servers. However, it can be easily done with ping with a Bash script. I summarize the script that I used and share it here: check-alive-server.sh. Usage: usage: ./check-alive-server.sh file Each…