Finds whitespace-separated words in @var{text} that match @var{pattern} and
replaces them with @var{replacement}. Here @var{pattern} may contain a
@samp{%} which acts as a wildcard, matching any number of any characters
-within a word. If @var{replacement} also contains a @samp{%}, the @samp{%} is
-replaced by the text that matched the @samp{%} in @var{pattern}. Words that
-do not match the pattern are kept without change in the output. Only the
-first @samp{%} in the @var{pattern} and @var{replacement} is treated this way;
-any subsequent @samp{%} is unchanged.
+within a word. The @var{pattern} must match the entire word, otherwise the
+word does not match. Words that do not match @var{pattern} are preserved
+in the result without change.
+
+If @var{replacement} also contains a @samp{%}, the @samp{%} is replaced by the
+text that matched the @samp{%} in @var{pattern}. Only the first @samp{%} in
+the @var{pattern} and @var{replacement} is treated this way; any subsequent
+@samp{%} is unchanged.
If @var{pattern} does not contain a @samp{%} then the entire word must compare
equal to be a match.
@cindex @code{\} (backslash), to quote @code{%}
@cindex backslash (@code{\}), to quote @code{%}
@cindex quoting @code{%}, in @code{patsubst}
-@samp{%} characters in @code{patsubst} function invocations can be
-quoted with preceding backslashes (@samp{\}). Backslashes that would
-otherwise quote @samp{%} characters can be quoted with more backslashes.
-Backslashes that quote @samp{%} characters or other backslashes are
-removed from the pattern before it is compared to file names or has a stem
-substituted into it. Backslashes that are not in danger of quoting
-@samp{%} characters go unmolested. For example, the pattern
-@file{the\%weird\\%pattern\\} has @samp{the%weird\} preceding the
-operative @samp{%} character, and @samp{pattern\\} following it. The
-final two backslashes are left alone because they cannot affect any
-@samp{%} character.
+@samp{%} characters in @code{patsubst} function invocations can be quoted with
+preceding backslashes (@samp{\}). Backslashes that would otherwise quote
+@samp{%} characters can be quoted with more backslashes. Backslashes that
+quote @samp{%} characters or other backslashes are removed from the pattern
+before it is compared to file names or has a stem substituted into it.
+Backslashes that are not in danger of quoting @samp{%} characters go
+unmolested. For example, the pattern @file{the\%weird\\%pattern\\} has
+@samp{the%weird\} preceding the operative @samp{%} character, and
+@samp{pattern\\} following it. The final two backslashes are left alone
+because they cannot affect any @samp{%} character.
Whitespace between words is folded into single space characters;
leading and trailing whitespace is discarded.