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