Linux get file contents

How can I display the contents of a text file on the command line?

I would like to display the contents of a text file on the command line. The file only contains 5-6 characters. Is there an easy way to do this?

9 Answers 9

Using cat

Since your file is short, you can use cat .

Using less

If you have to view the contents of a longer file, you can use a pager such as less .

You can make less behave like cat when invoked on small files and behave normally otherwise by passing it the -F and -X flags.

I have an alias for less -FX . You can make one yourself like so:

If you add the alias to your shell configuration, you can use it forever.

Using od

If your file contains strange or unprintable characters, you can use od to examine the characters. For example,

$ cat file (ÐZ4 ?o=÷jï $ od -c test 0000000 202 233 ( 320 K j 357 024 J 017 h Z 4 240 ? o 0000020 = 367 \n 0000023 

Does less have any clear advantages over other pager programs like pg , or does it just boil down to personal preference?

@SamWeinberg: less has more features than pg . Take a look at the less(1) and pg(1) manpages. There are other pagers as well. Take a look at unix.stackexchange.com/questions/81129/…. less is probably the most widely-used pager but which one you use comes down to personal preference.

Even though everybody uses cat filename to print a files text to the standard output first purpose is concatenating. From cat’s man page:

cat — concatenate files and print on the standard output

Now cat is fine for printing files but there are alternatives:

The ( ) return the value of an expression, in this case the content of filename which then is expanded by $ for echo or printf .

This does exactly what you want and is easy to remember.

Here is an example that lets you select a file in a menu and then prints it.

#!/bin/bash select fname in *; do # Don't forget the "" around the second part, else newlines won't be printed printf "%s" "$(<$fname)" break done 

Your update: " < filename is exactly what you want, . " is misleading. Overall, although this is an interesting discussion on alternatives, I think cat is simpler.

Tools for handling text files on unix are basic, everyday-commands:

In unix and linux to print out whole content in file

You can use following command to display content of a text file.

One option is to use more

However it does not have all the feature added by less .
One simple example is that you can't scroll back up in the output. Generally it has been superceeded by less - which was named in jest because

I always use $ less "your file here" , as it is very simple, provides a built in interactive grep command, and gives you an easy to use interface that you can scroll with the arrow keys.

(It is also included on nearly every *nix system)

less is the overkill-version of more (compare man less with man more ), and for me it has two annoying features: 1) it switches to the alternate screen buffer, when less terminates, the file you were just viewing vanishes 2) at EOF you have to explicitly type q (I know, there's an option for this). So one of my first actions in a new environment is setting export PAGER=/bin/more in my profile and use more all the time.

@ott--: 1) Try out the -X flag. 2) Try out the -E flag. less has a more emulation mode. You can enable it by setting the LESS_IS_MORE environmental variable. You can scroll upwards in the more emulation mode.

Though, in general, I do agree that less is overly-complicated. Its ability to run external commands is a perfect example of its over-complexity.

@EvanTeitelman I've always found the grep functionality extremely useful myself, @ott-- I find that because of it's emulation of more , and it's many additional features, it does the job very well.

If its a large file, and you want to search some specific part, you can use

 cat filename | grep text_to_search -ni 

Also you can use more interactive Vim editor (or vi editor if you do not have Vim):

 vim filename Or vi filename

Vim/vi is a great editor, can also be used as a reader in "Normal Mode" or using -R option, it has many features that will help you in browsing through the file.

Shorter for vim -R is view . But keep in mind that it not likes redirections, as discussed in xargs and vi - “Input is not from a terminal”.

thanks @manatwork for the heads up! I have recently started using Vim and I like it because of its several features. Regarding redirections, I forgot about that, thanks for reminder. As of now, I am working on a remote VM, where I use ssh without GUI interface, therefore, Vim is of great use, when any other GUI editor cannot work, that's why I emphasized Vim here.

Use cat command to display the content of filename.

Use vim command to edit file.

Shall I compare thee to a summer’s day? Thou art more lovely and more temperate. Rough winds do shake the darling buds of May, And summer’s lease hath all too short a date. Sometime too hot the eye of heaven shines, And often is his gold complexion dimmed; And every fair from fair sometime declines, By chance or nature’s changing course untrimmed. But thy eternal summer shall not fade Nor lose possession of that fair thou ow’st, Nor shall Death brag thou wand’rest in his shade, When in eternal lines to time thou grow’st. So long as men can breathe or eyes can see, So long lives this, and this gives life to thee. 

Clearly, cat is going to be the most popular answer to this question, but the code examples above will also provide the desired output (file courtesy of Shakespeare, via Project Gutenberg). However learning basic one-liners using Perl and/or Raku has its merits, simply because you can get an awful lot of work done with them.

Grep through a file, return matching lines:

~$ #Perl: ~$ perl -ne 'print if /eternal/' Sonnet_18.txt But thy eternal summer shall not fade When in eternal lines to time thou grow’st. ~$ #Raku: ~$ raku -ne '.put if /eternal/' Sonnet_18.txt But thy eternal summer shall not fade When in eternal lines to time thou grow’st. 

Substitute one bit of text with another, redirect output to a new file:

~$ #Perl: ~$ perl -pe 's/eternal/forevermore/g' Sonnet_18.txt > new_sonnet.txt ~$ #Raku: ~$ raku -pe 's:g/eternal/forevermore/' Sonnet_18.txt > new_sonnet.txt 

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View the Contents of a File in Linux Command Line

The usual way to view the contents of a file is to simply open it in a text editor. However, for more quick viewing and in fact, also for automating in a shell script, the method of using a text editor does not suit.

There are many commands in Linux to solve this problem: to display the file contents on the command line.

Let us take a look at a few such commands.

View Contents of File Using Cat Command

A cat command is the most commonly used command to view the contents of a file. The syntax to use cat is quite simple, as shown below:

View File Contents By Line Numbers

The nl is another command in Linux which displays the contents of a file. It stands for ‘Number lines’, as the output displayed by this command is numbered lines.

The nl command has even more options to format the output numbering in various ways. However, to simply display the contents, it can be used as discussed above.

View File Contents Using More or Less Commands

The ‘more’ or ‘less’ are pretty much the same command in Linux. They display a file on the terminal one page at a time and are thus very useful in displaying large files.

For smaller files, ‘more’ works the same as the cat command, whereas ‘less’ works the same for both larger and smaller files.

The output of ‘less’ is displayed on an overlay screen, and can be exited by pressing ‘q’ . Thus the output is not permanently written to the screen.

View File Contents Using head or tail Commands

The head command is used to print the first 10 lines of a file, instead of printing the whole file. Similar tail prints the last 10 lines of a file.

For example, the following respectively print the first and last 10 lines of the huge logfile ‘/var/log/syslog‘.

If you need to print a different number of top or bottom lines of the file, use the argument ‘-n’ .

$ head -n5 /var/log/syslog $ tail -n5 /var/log/syslog

Conclusion

Today we learned about various ways to display the contents of a file in the Linux command line. If you know any other cool way to display file contents in the command line, do share it with everyone in the comments below!

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What is the shell command to display contents of a file?

For viewing HTML files you can also use lynx , links , elinks or w3m which are text-mode browsers. They can also be used to view .txt files.

file : Display the type of file cat : Display the content of the file and outputs it on stdout.

You can use vi, emacs command to edit the file in Unix environment. If you do not have expertise in using vi/emacs you might find it little difficult to edit the file.

If you have X11 enabled, You can use a number of Linux editors like gvim, kate, kwrite, kdevelop etc.

Kwrite is my personal favorite in Linux.

Or, less or more . See the man pages for more information. 🙂

cat Works fine with txt or html. (or less or more if you want tosee it page by page) or any text ediotr. (vi, emcas, gedit. ).

Also know that if it's a binary file it's may contain control char that will do some displeasing things with your terminal (like changing charset). If that happen use reset to put it back in sane state.

You can also use file on file before displaying it's content, the system will guess it's type (based on content not filename name) and show it to you.

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