The replace utility program changes strings in place in files or on the standard input.

Invoke replace in one of the following ways:

replace from to [from to] ... -- file_name [file_name] ...
replace from to [from to] ... < file_name

from represents a string to look for and to represents its replacement. There can be one or more pairs of strings.

Use the -- option to indicate where the string-replacement list ends and the file names begin. In this case, any file named on the command line is modified in place, so you may want to make a copy of the original before converting it. replace prints a message indicating which of the input files it actually modifies.

If the -- option is not given, replace reads the standard input and writes to the standard output.

replace uses a finite state machine to match longer strings first. It can be used to swap strings. For example, the following command swaps a and b in the given files, file1 and file2:

replace a b b a -- file1 file2 ...

replace supports the following options.