paste

The paste command line tool is used to merge lines from multiple files. It is commonly used to merge columns of data.

It takes input from one or more files, separates each line into fields using a delimiter, and then combines the corresponding fields from each line of input into a single line of output.

The default delimiter used by paste is the tab character, but it can be changed using the -d option.

The lines from each file are merged sequentially, and if a file has fewer lines than the others, paste will use empty fields for the missing lines.

Using the -s option, paste can be used to merge the lines of a single file into a single line, separated by the delimiter.

By default, paste writes the merged lines to the standard output, but an output file can be specified using the -o option.

If no input files are provided, paste reads from the standard input.

The paste command is often used in conjunction with other command line tools such as cut, sort, and awk to manipulate and analyze data.

It is particularly useful when dealing with log files, tabular data, and CSV files.

Overall, paste is a versatile and handy command line tool for combining lines from multiple files based on a delimiter.