display contents of file

gr8linux · 07-08-2009, 01:48 PM

can we use echo command for displaying the contents of a particular file....................

nuwen52 · 07-08-2009, 02:05 PM

You can use "cat" to display the contents of a file.

NeddySeagoon · 07-08-2009, 02:17 PM

gr8linux,

You can also use more and less, which display a file a page at a time, where page is whatever fits in the window. more only allows you to move forward in the file, less allows backwards scrolling too.

Telengard · 07-08-2009, 02:28 PM

Yes echo can be used to display the contents of a file. The way I did it is by command substitution. The basic syntax is echo "`cat filename`". The contents of filename will be cat-ted and the standard output of cat will be substituted as a parameter for echo.

Code:

echo "`cat hello.c`"
#include <stdio.h>

int main( void ) {
  printf( "Hello, World!\n" );
  return 0;
}

There is an alternate syntax for command substitution using $() instead of back-quotes.

Code:

echo "$(cat hello.c)"
#include <stdio.h>

int main( void ) {
  printf( "Hello, World!\n" );
  return 0;
}

I have tried using redirections but it just doesn't work because echo does not receive its parameters from STDIN. Maybe someone else knows how to do it using redirections?

abi0909 · 07-08-2009, 02:47 PM

When you can simply cat a file, why should we be using echo unless a specific purpose. I would always be simple.

Tinkster · 07-08-2009, 02:54 PM

Quote:

Originally Posted by gr8linux

can we use echo command for displaying the contents of a particular file....................

Heh ... what is it with your obsession with 'echo'? =D
More than 60% of your posts are about echo ...

Cheers,
Tink

b0uncer · 07-08-2009, 02:56 PM

Or, if you need to print only particular parts of a file, you could use other tools such as awk (which may be a little overkill though). An example of awk printing a whole file is pretty useless (just one print statement), and more useful examples would be too plenty, so if you're interested you should search for howto or some awk manual. There are many available on the net, and the examples should give you a quick overview of what it is; just don't get fooled, awk can do a lot more than the examples (especially one-liners) can show. What I typically do with it is extract column data from files or do calculations where the data involved needs to be extracted from certain lines/columns in the file, leaving other content out.

Anyway, in principle awk does just as well as cat, even if it is quite a bit more complex.

Telengard · 07-08-2009, 05:14 PM

Quote:

Originally Posted by abi0909

When you can simply cat a file, why should we be using echo unless a specific purpose. I would always be simple.

Only the OP could possibly answer that question. IMHO my own reply comes closest to answering his question. I do agree with everyone here that cat, more, less, and awk are all much better ways to simply display the contents of a file.

i92guboj · 07-08-2009, 05:36 PM

Quote:

Originally Posted by Tinkster

Heh ... what is it with your obsession with 'echo'? =D
More than 60% of your posts are about echo ...

Cheers,
Tink

I was also wondering about that. Maybe he wants to start a new OS or something (echOS?).

Jokes apart, the only way I know is to use stdout as an argument for echo, as someone else pointed above, which is redundant and silly as also pointed above by someone else.

Code:

echo $(whatever)

You could invent lots of creative ways to do silly things with echo like

Code:

echo | xargs < myfile.txt

And so on, that doesn't solve the main point anyway: you should be using cat.