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RSUB(1) General Commands Manual RSUB(1) NAME rsub -- substitute lines or block of text SYNOPSIS rsub [-A] -r line_regex -l line_text target rsub target < block_content DESCRIPTION rsub is shipped to remote machines by rset(1) to provide a standard method of modifying configuration parameters within a file. Two modes of opera- tion are supported: line substitution and block replacement. Single line replacements are defined by the flags -r and -l, while the con- tent for a text block is provided on STDIN. The arguments for line substitution are as follows: -A Append line if the pattern is not found. -r A regular expression matching the line to replace. -l The replacement text for a matching line. Newlines are not permit- ted as part of the replacement string. ENVIRONMENT RSUB_DIFF_ARGS Arguments for diff(1) tool. The default is "-U 2". RSUB_START RSUB_END Define the beginning and ending markers when updating a block of text. EXIT STATUS The rsub utility exits with one of the following values: 0 Target file was updated 1 No changes were made, or an error occurred 2 Incorrect parameters 3 File not found EXAMPLES Ensure a single configuration parameter is set $SD/rsub -r '^AllowTcpForwarding .+' -l 'AllowTcpForwarding yes' \ /etc/ssh/sshd_config Update a managed block of text $SD/rsub /etc/fstab <<-CONF /dev/ada0p1 /vm ufs rw 0 0 CONF SEE ALSO awk(1), rinstall(1) FreeBSD ports 15.quarterly January 17, 2026 RSUB(1)
NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | EXIT STATUS | EXAMPLES | SEE ALSO
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