names.txt and roles.txt have the same number of lines, with corresponding data on each line.
Join each pair with a comma as name,role.
Which command is appropriate?
paste combines input files horizontally by corresponding line number. The -d option selects the output delimiter.
Detailed explanation
paste -d, names.txt roles.txtCorrect. paste joins each line pair and uses a comma between the fields.
Correct. paste joins each line pair and uses a comma between the fields.
cat names.txt roles.txtIncorrect. cat prints the second file after the first rather than joining lines.
Incorrect. cat prints the second file after the first rather than joining lines.
cut -d, -f1 names.txt roles.txtIncorrect. cut selects fields; it does not combine two files line by line.
Incorrect. cut selects fields; it does not combine two files line by line.
sort names.txt roles.txtIncorrect. sort orders input lines instead of pairing corresponding records.
Incorrect. sort orders input lines instead of pairing corresponding records.
Try it yourself
An example you can run in a temporary verification environment.
paste -d, <(printf 'alice
bob
') <(printf 'admin
viewer
')Expected result
alice,admin
bob,viewerKey points
- paste joins corresponding lines
- -d sets the delimiter
- cat concatenates vertically
Notes
- Environment: Bash 5.2 / GNU coreutils 9.x
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.