Name¶

pesubst — perl-regexp stream substitution

Syntax¶

pesubst [-f] [-s pattern] [-d pattern] [-m modifiers] file...

Description¶

pesubst can substitute strings in streams and files, and does so by using the Perl engine. It obsoletes sed(1) for simple substitution tasks.

Options¶

-f

Fill the replacement string with NULs to bring it up to the size of the original string.

-s pattern

Source pattern to search for in files. This can be any valid Perl regular expression. Files are slurped in as a whole, so matching across newlines should be no problem (with the -ms flag).

-d pattern

Destination (replacement) string. This can be any valid string Perl accepts. For details see the perlre(1) manpage.

-m modifiers

A string of modifiers to apply to the regex. See below.

Modifiers¶

e

Evaluate the right side as an expression.

g

Replace globally, i.e., all occurrences. This is always enabled in pesubst.

i

Do case-insensitive pattern matching.

m

Treat string as multiple lines. That is, change "^" and "$" from matching the start or end of the string to matching the start or end of any line anywhere within the string.

o

Compile pattern only once.

s

Treat string as single line. That is, change "." to match any character whatsoever, even a newline, which normally it would not match.

x

Extend your pattern's legibility by permitting whitespace and comments.

Examples¶

Change all occurrences of foo (case-insensitive) to bar:

	pesubst -s foo -d bar -ms myfile

Change all Shell-style comments into C++ ones:

	pesubst -s '^#' -d // -mm myfile

Using both the "m" and "i" flags:

	pesubst -s '^#INCLUDE\s+' -d '#include ' -mmi myfile.c

See also¶

hxtools(7), pegrep(1)