RSUB(1) General Commands Manual RSUB(1)

substitute lines in a file or append if not found

rsub [
] -r line_regex -l line_text target

rsub target < block_content

rsub is shipped to remote machines by rset(1) to provide a standard method of modifying configuration parameters within a file. Two modes of operation are supported: line substitution and block replacement.
line replacements are defined by the flags -r and -l, while the content for a text block is provided on STDIN.
The arguments for line subsitution are as follows:
Append line if the pattern is not found.
A regular expression matching the line to replace.
The replacement text for a matching line. Newlines are not permitted as part of the replacement string.

When updating a block of text, RSUB_START and RSUB_END define the beginning and ending markers.

The rsub utility exits with one of the following values:
Target file was updated
No changes were made, or an error occurred
Incorrect parameters
File not found

awk(1), rinstall(1)
November 7, 2018 OpenBSD 6.4