Tips and Tricks

To find and replace one or more occurences of a given text pattern with a new text string, use the s[ubstitute] command. There are a variety of options, but these are what you most probably want: :%s/foo/bar/g find each occurance of 'foo' and replace it with 'bar' without asking for confirmation :%s/foo/bar/gc find each occurance of 'foo' and replace it with 'bar' asking for confirmation first :%s/ /bar/gc find (match exact word only) and replace each occurance of 'foo' with 'bar' :%s/foo/bar/gci find (case insensitive) and replace each occurance of 'foo' with 'bar' :%s/foo/bar/gcI find (case sensitive) and replace each occurance of 'foo' with 'bar' NB: Without the 'g' flag, replacement occurs only for the first occurrence in each line. For a full description and some more interesting examples of the substitute command refer to :help substitute See ...

When you like to execute the same command continuously (run a command in a loop) this is very helpful while true;do date;sleep 2;done This executes the date command continuously. A sleep given for a break. After the execution of the command once, it waits that many duration before it executes the command the next time.

While typing a search command, show immediately where the so far typed pattern matches. The matched string is highlighted. If the pattern is invalid or not found, nothing is shown. The screen will be updated often, this is only useful on fast terminals. :set incsearch To disable it :set noincsearch

To enable case insensitive search in vi editor :set ignorecase To disable it :set noignorecase Find out more from www.tech-recipes.com/unix_tips406.html

Use the -g option while building it so as to include the debug symbols. This will help to put breakpoints on line numbers and/or function names while using grub debugger (gdb) gcc -g cFile.c g++ -g cppFile.cpp

To rename a set of files to a name starting with a particular pattern (here the pattern is taken to be to start the filename with "MyFile_" files = `ls -1`;for file in $files; do mv $file MyFile_$file ; done Dissection: ls -1 ls is the command in linux to list the files in the present directory The parameter -1 will list one file a line "files" is a variable which has the list of all the files listed by the command ls -1 files = `ls -1` save the result of ls -1 to a variable called files Remember to put the command inside a pair of back ticks ` (the key is generally found just before the key "1" in the keyboard) Significance of ` (backtick) for file in $files Loop through each file name available in the variable files do mv $file MyFile_$file; done (The do - done loop) Executes the command given after do End the do with a done