LinuxQuestions.org - [SOLVED] bash to print words/lines horizontally

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nitya

02-20-2013 04:45 AM

bash to print words/lines horizontally

Hi All,
I have a test file with below entries

Code:

$ cat /tmp/test 

RedHat

Cent

Fedora

Suse

Ubuntu

Now how can I print these entries horizontally i.e I am expecting the output to be as

Code:

RedHat Cent Fedora Suse Ubuntu

Thanks in advance for your kind help.

druuna

02-20-2013 04:54 AM

Using tr:

Code:

cat infile | tr "\n" " "

Using awk:

Code:

awk 'BEGIN{ ORS=" " }{ print }' infile

There are probably other ways as well.

millgates

02-20-2013 05:03 AM

pure bash:

Code:

foo="$(<infile)"

echo "${foo//$'\n'/ }"

Code:

<infile mapfile -t array

echo "${array[@]}"

Of course, there's also Perl, sed and many others.

nitya

02-20-2013 05:37 AM

Thank you both, worked as expected. But druuna both of your commands output are in the same line where will be "user@hostname:~$", it is okay I can cut and paste the output.
Once again thanks a lot druuna and millgates.

millgates

02-20-2013 06:36 AM

Quote:

Originally Posted by nitya (Post 4895854)

both of your commands output are in the same line where will be "user@hostname:~$"

That's because the first example just replaces all newlines with spaces, including the trailing one. So there's no newline at the end of output and the bash prompt ends up on the same line. The awk example reads the file line by line and outputs them delimited by spaces. Again, no newline at the end of output. My examples work in a similar way, but I use echo to print the result, which automatically appends a newline to whatever it prints (this can be overriden by the -n switch). If you want those trailing \ns to be there, you can print them yourself:

Code:

cat infile | tr "\n" " " && echo

and

Code:

awk 'BEGIN{ ORS=" " }{ print }END{ print "\n"}' infile

Code:

awk 'BEGIN{ ORS=" " }{ print }' infile && echo

But it depends on what you want to do with the output. Do you want to use it in a script? Put it in a file?

RaviTezu

02-20-2013 07:33 AM

Adding to druuna post.

Quote:

cat infile | tr "\n" " " | grep -v @

Will work. i have ignored "user@hostname:~$" using grep command. :P

grail

02-20-2013 09:58 AM

Code:

paste -sd' ' file

colucix

02-20-2013 10:10 AM

Code:

echo $(<file)

nitya

02-21-2013 02:58 AM

Thank you all for giving lot of ways to achieve this.

Code:

@millgates

foo="$(<infile)"

echo "${foo//$'\n'/ }"



<infile mapfile -t array

echo "${array[@]}"



cat infile | tr "\n" " " && echo



awk 'BEGIN{ ORS=" " }{ print }' /tmp/test && echo



@RaviTezu

cat infile | tr "\n" " " | grep -v @



@grail

paste -sd' ' file



@colucix

echo $(<file)

All above commands worked great. This thread helped me a lot to know about different commands.
Once again thank you all.

shivaa

02-21-2013 04:51 AM

One more way: :)

Code:

~$ for word in $(cat /tmp/test); do echo -n "$word "; done; echo

millgates

02-21-2013 05:11 AM

Quote:

Originally Posted by shivaa (Post 4896567)

One more way: :)

Code:

~$ for word in $(cat /tmp/test); do echo -n "$word "; done; echo

In this case it will work, but keep in mind that reading files with for like this is generally a bad idea.

Code:

~$ while read word; do echo -n "$word"; done < /tmp/test; echo

might be a bit better.

shivaa

02-21-2013 05:19 AM

Quote:

Originally Posted by millgates;

In this case it will work, but keep in mind that reading files with for like this is generally a bad idea.

Oh yes, you're right.. how can I forget David the H's lession on use while instead of for.

@Everyone:
How can I read a file (data stream, variable) line-by-line (and/or field-by-field)? (Link)
And
Why you don't read lines with "for" (Link)

whizje

02-21-2013 05:32 AM

Code:

xargs echo < file

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