Print two files in two columns

command-line text-formatting paste

9,564

Solution 1

What about paste file{1,2}| column -s $'\t' -tn?

looooooooong line line  hello
line                    world

This is telling column to use Tab as columns' separator where we takes it from the paste command which is the default seperator there if not specified; generally:

paste -d'X' file{1,2}| column -s $'X' -tn

where X means any single character. You need to choose the one which granted that won't be occur in your files.
The -t option is used to determine the number of columns the input contains.
This will not add long tab between two files while other answers does.
this will work even if there was empty line(s) in file1 and it will not print second file in print area of file1, see below input/ouput

Input file1:
```
looooooooong line

line
```
Input file2:
```
hello
world
```
Output:
```
looooooooong line  hello
                   world
line
```

Solution 2

With single pr command:

pr -Tm file[12]

-T (--omit-pagination) - omit page headers and trailers, eliminate any pagination by form feeds set in input files
-m (--merge) - print all files in parallel, one in each column

Solution 3

Try:

paste -d '\n' file1 file2 | xargs -d '\n' printf '%-30s  %-30s\n'

Inspired by @Kusalananda's solution.

^{Note: The -d parameter of xargs is only available on GNU version, but not on BSD.}

Solution 4

A portable solution:

$ paste file1 file2 | awk -F'\t' '{ printf("%-30s %s\n", $1, $2) }'
looooooooong line              hello
line                           world

This uses paste to produce a tab-delimited input for awk.

The awk script simply takes the two tab-delimited fields and outputs them using printf(). A column of 30 characters is reserved for the first file. The %-30s means "30 positions of string data with left alignment". Removing the - would produce a column aligned to the right, and changing 30 would change the column width.

It also deals with uneven length files. Here I've added lines to the second file:

looooooooong line              hello
line                           world
                               hello
                               world
                               hello
                               world

And, when reversing the order of the files on the command line:

hello                          looooooooong line
world                          line
hello
world
hello
world

View more solutions

9,564

belkka

Updated on September 18, 2022

Comments

belkka over 1 year
I want to print two files in two columns -- first file on the left side and second on the right side.

paste doesn't do the job, because it can only insert a character as delimiter, so if first file lines have different length output will be twisted:
```
$ cat file1
looooooooong line
line
$ cat file2
hello
world
$ paste file1 file2
looooooooong line   hello
line    world
```
If it was a command to add trailing spaces like fmt --add-spaces --width 50 the problem would be solved:
```
$ paste <(fmt --add-spaces --width 50 file1) file2
looooooooong line                                 hello
line                                              world
```
But I don't know a simple way to do this.

So how to merge and print several files horizontally without twisting? Actually, I just want to look at them simultaneously.

UPD: command to add trailing spaces does exist (for example, xargs -d '\n' printf '%-50s\n')

But solution like
```
$ paste <(add-trailing-spaces file1) file2
```
does not work as expected when file1 has fewer lines than file2.
- Olaf Dietsche over 6 years
  
  You may use awk for your hypothetical fmt command, see stackoverflow.com/a/9394541/1741542 as an awk
Kusalananda over 6 years

What does the -T do?
belkka over 6 years

Generally paste -d @ file1 file2 | column -t -n -s @ where @ is any delimiter that is not contained in files.
belkka over 6 years

This can truncate long lines without any warning, but I like it.
αғsнιη almost 6 years

@belkka exactly
paradroid over 4 years

I had been trying this but without the $. This is the answer for me, but could you explain what the $ is doing here?
αғsнιη over 4 years

@paradroid please see gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.ht‌ml
Ulysse BN over 4 years

On my mac I had to use pr -tm file[12]. (minus -t)