Display two files side by side
LinuxShellUnixCommand LineGnu CoreutilsLinux Problem Overview
How can 2 unsorted text files of different lengths be display side by side (in columns) in a shell
Given one.txt and two.txt:
$ cat one.txt
apple
pear
longer line than the last two
last line
$ cat two.txt
The quick brown fox..
foo
bar
linux
skipped a line
Display:
apple The quick brown fox..
pear foo
longer line than the last two bar
last line linux
skipped a line
paste one.txt two.txt almost does the trick but doesn't align the columns nicely as it just prints one tab between column 1 and 2. I know how to this with emacs and vim but want the output displayed to stdout for piping ect.
The solution I came up with uses sdiff and then pipes to sed to remove the output sdiff adds.
sdiff one.txt two.txt | sed -r 's/[<>|]//;s/(\t){3}//'
I could create a function and stick it in my .bashrc but surely a command for this exists already (or a cleaner solution potentially)?
Linux Solutions
Solution 1 - Linux
You can use pr to do this, using the -m flag to merge the files, one per column, and -t to omit headers, eg.
pr -m -t one.txt two.txt
outputs:
apple The quick brown fox..
pear foo
longer line than the last two bar
last line linux
skipped a line
See Also:
Solution 2 - Linux
To expand a bit on @Hasturkun's answer: by default pr uses only 72 columns for its output, but it's relatively easy to make it use all available columns of your terminal window:
pr -w $COLUMNS -m -t one.txt two.txt
Most shells will store (and update) your terminal's screenwidth in the $COLUMNS shell variable, so we're just passing that value on to pr to use for its output's width setting.
This also answers @Matt's question:
> Is there a way for pr to auto-detect screen width?
So, no: pr itself can't detect the screenwidth, but we're helping it out a bit by passing in the terminal's width via its -w option.
Note that $COLUMNS is a shell variable, not an environment variable, so it isn't exported to child processes, and hence the above approach will likely not work in scripts, only in interactive TTYs... see https://stackoverflow.com/questions/1780483/ for alternative approaches.
Solution 3 - Linux
If you know the input files have no tabs, then using expand simplifies https://stackoverflow.com/users/249545/oyss">@oyss</a>'s https://stackoverflow.com/a/13343584/4263262">answer</a>;:
paste one.txt two.txt | expand --tabs=50
If there could be tabs in the input files, you can always expand first:
paste <(expand one.txt) <(expand two.txt) | expand --tabs=50
Solution 4 - Linux
paste one.txt two.txt | awk -F'\t' '{
if (length($1)>max1) {max1=length($1)};
col1[NR] = $1; col2[NR] = $2 }
END {for (i = 1; i<=NR; i++) {printf ("%-*s %s\n", max1, col1[i], col2[i])}
}'
Using * in a format specification allows you to supply the field length dynamically.
Solution 5 - Linux
There is a sed way:
f1width=$(wc -L <one.txt)
f1blank="$(printf "%${f1width}s" "")"
paste one.txt two.txt |
sed "
s/^\(.*\)\t/\1$f1blank\t/;
s/^\(.\{$f1width\}\) *\t/\1 /;
"
Under [tag:bash], you could use printf -v:
f1width=$(wc -L <one.txt)
printf -v f1blank "%${f1width}s"
paste one.txt two.txt |
sed "s/^\(.*\)\t/\1$f1blank\t/;
s/^\(.\{$f1width\}\) *\t/\1 /;"
(Of course @Hasturkun 's solution pr is the most accurate!):
Advantage of sed over pr
You can finely choose separation width and or separators:
f1width=$(wc -L <one.txt)
(( f1width += 4 )) # Adding 4 spaces
printf -v f1blank "%${f1width}s"
paste one.txt two.txt |
sed "s/^\(.*\)\t/\1$f1blank\t/;
s/^\(.\{$f1width\}\) *\t/\1 /;"
Or, for sample, to mark lines containing line:
f1width=$(wc -L <one.txt)
printf -v f1blank "%${f1width}s"
paste one.txt two.txt |
sed "s/^\(.*\)\t/\1$f1blank\t/;
/line/{s/^\(.\{$f1width\}\) *\t/\1 |ln| /;ba};
s/^\(.\{$f1width\}\) *\t/\1 | | /;:a"
will render:
apple | | The quick brown fox..
pear | | foo
longer line than the last two |ln| bar
last line |ln| linux
| |
|ln| skipped a line
Solution 6 - Linux
If you want to know the actual difference between two files side by side, use diff -y:
diff -y file1.cf file2.cf
You can also set an output width using the -W, --width=NUM option:
diff -y -W 150 file1.cf file2.cf
and to make diff's column output fit your current terminal window:
diff -y -W $COLUMNS file1.cf file2.cf
Solution 7 - Linux
remove dynamically field length counting from Barmar's answer will make it a much shorter command....but you still need at least one script to finish the work which could not be avoided no matter what method you choose.
paste one.txt two.txt |awk -F'\t' '{printf("%-50s %s\n",$1,$2)}'
Solution 8 - Linux
Find below a python based solution.
import sys
# Specify the number of spaces between the columns
S = 4
# Read the first file
l0 = open( sys.argv[1] ).read().split('\n')
# Read the second file
l1 = open( sys.argv[2] ).read().split('\n')
# Find the length of the longest line of the first file
n = len(max(l0, key=len))
# Print the lines
for i in xrange( max( len(l0), len(l1) ) ):
try:
print l0[i] + ' '*( n - len(l0[i]) + S) + l1[i]
except:
try:
print ' ' + ' '*( n - 1 + S) + l1[i]
except:
print l0[i]
Example
apple The quick brown fox..
pear foo
longer line than the last two bar
last line linux
skipped a line
Solution 9 - Linux
diff -y <file1> <file2>
[root /]# cat /one.txt
apple pear longer line than the last two last line[root /]# cat /two.txt
The quick brown fox.. foo bar linux[root@RHEL6-64 /]# diff -y one.txt two.txt
apple | The quick brown fox.. pear | foo longer line than the last two | bar last line | linux