UNIX for Beginners Questions & Answers

I will like to merge several files using 'cat', but I observe the output is not consistent. the merge begins at the last line of the first file.

Code:

file1.txt:
1234
1234
1234

file2.txt:
aaaa
bbbb
cccc
dddd

cat file1.txt file2.txt > file3.txt
file3.txt:
1234
1234
1234aaaa
bbbb
cccc
dddd

Could this be an error associated with the command or a bug?
Thanks.

Hello geomarine,

It is working well and fine for me and moreover I am getting different Input_file(s) output from new line only as follows.

Code:

 
cat file1.TXT file2.TXT > file3.TXT
cat file3.TXT
1234
1234
1234
aaaa
bbbb
cccc
dddd

Could you please check once if your Input_file is having carriage returns in it? By doing cat -v Input_file if yes then kindly remove them from following command.

Code:

 
tr -d '\r' < Input_file > temp_file && mv temp_file Input_file

Let us know how it goes then, I hope this helps.

Thanks,
R. Singh

Probably the last line does not have a closing linefeed character. Proper Unix files are required to have this..

See if this works:

Code:

echo | cat file1.txt - file2.txt > file3.txt

Thanks RavinderSingh13 and Scrutinizer . I check to see if there are carriage returns with:

Code:

cat -v Input_file

result:

Code:

cat -v file3.txt 
1234^M
1234^M
1234aaaa^M
bbbb^M
cccc^M
dddd

using this command suggested:

Code:

tr -d '\r' < file1.txt > temp_file && mv temp_file file1.txt

the carriage return was removed. However, the result is still same:

Code:

1234
1234
1234aaaa
bbbb
cccc
dddd

when I use this command:

Code:

echo | cat file1.txt - file2.txt > file3.txt

the result is:

Code:

123412341234aaaabbbbccccdddd

I am using BASH shell.

What OS are you using?

Windows 7 Professional

You have shown us that you have two input files with <carriage-return><new-line> line separators and no final line terminators (i.e., DOS text file format).

You have shown us several outputs that you have gotten from what you originally tried and form what others have suggested and you have told us that none of them are what you want. But, from your description and from your examples, I don't know whether you're trying to get all lines from each input file combined into single lines (one for each input file) in the output, all input lines from all files combined into a single output line (sequentially or pairwise), pairs of lines (one from each input file) combined into output lines, or something else.

Please show us the output you are hoping to get from your sample input files and tell us whether you want that output to be in DOS text file format (like your input files) or in standard UNIX text file format (i.e. <new-line> line terminators on every line with no <carriage-return> characters).