In above commands, s stands for substitute(specified the action to be performed). Sed s/cash/trash/g # Replace every occurrence of cash with trash It allow us to use search and replace specific data. By default it takes tab character as a seperator, to specify any other we use -d option, as here we specified space as a seperator. f stands for field or column which we want, as in second example we want both 1 and 2 field so we input these two. We used the cut filter with two command line options -f and -d. cut :- It is used when the text is seperated into columns and we want only certain columns.You can use two command line options at a time e.g. l for lines only, -w for words only, -m for characters only. It counts the words, lines, characters by default, though you can restrict the output using command line options.

The space before the number is the padding we gave. #there would be more lines in your output The output would be somewhat like this: 1. What -s does is that, it specifies what should come after the number and what -w does is that it specifies how much padding before the number should be given.

We used two command line option -s and -w. The first command is self-explanatory, though the second one needs a little attention. Nl sample.txt # This will show each line with line number As the name suggests, it shows the line number alongwith each line. Sort sample.txt # This will short the file sample.txt alphabetically By default it sorts alphabetically, though we can change it’s behaviour using many command line options. sort :- It sorts its input as the name says.Tail -6 sample.txt # This will print the last 6 lines of the file tail :- It’s a program that prints last -n lines of its input.Head -4 sample.txt # This will print the first 4 lines of the file Head sample.txt # This will print the first 10 lines of the file head :- It’s a program that prints first -n lines of its input.So, don’t forget to look for the man page for each of these filters. These filters have various command line options which provides more flexibility to the output given by the filters. Filtersįilters are the programs that take textual data as an input and format it according to the applied filter. Just like that, they can be used widely and saves a lot of time with the required result. mv home/.?g home/images/, this command will move each jpg or png files into the given folder. I have used ls command only, though you can use other commands also. These are only a few examples where you can use wildcards. Therefore, the command will show all files and folders which do not start with the letters between a to k. It can be used inside a range to exclude the things which are included in range. ls * :- Here, I used a character ^(caret).ls ** :- This will show every file whose name has a digit in it.ls * :- This will list files and folders that ends with either q or v.ls ?p* :- This command will list all files and folders whose second letter is p.ls *.txt :- This command will list every file and folder whose extension is.ls b* :- This command will list all the files and folders which starts with b irrespective of the letters come after it.(Square Brackets) : It represents a range of characters.? (Question Mark) : It represents only a single character.* (Star) : It represents zero or more characters.There are basically three wildcards which are used often: These are usually used with linux commands. They greatly increase the flexibility and efficiency of searches in any nix-operating system. WildcardsĪ wildcard is a substitute for a group of characters, which results in formation of a pattern defining a set of files and directories. This can be done by using Wildcards, Filters, Regex and piping. There are some amazing options when you can control the view of the output according to you. Have you ever thought, how that would be easy if a set of files can be operated over by using just one command. So I’ll suggest you to go through An Introduction to Linux. If you don’t know the basic commands then it might be little difficult to get over your head.

Today we will advance our knowledge a bit more with some new topics.

Ls grep regex