Add a pass to try to remove empty words due to substitution.

The use of -S/-E/-I can lead to empty words, they must be deleted in all
cases except in column mode. In column mode, substitutions involving
empty words can lead to misalignments, so it is necessary to prohibit
them and terminate the program. These substitutions have to be made
with other tools before using this utility.

1 files changed, 12 insertions, 0 deletions

diff --git a/smenu.1 b/smenu.1
index 0162443..39e512e 100644
--- a/smenu.1
+++ b/smenu.1
@@ -513,6 +513,18 @@ substituted by any other character except \fISPACE\fP, \fI\\t\fP,
 In the four previous options, \fIregex\fP is a \fBPOSIX\fP
 \fBE\fPxtended \fBR\fPegular \fBE\fPxpression.
 For details, please refer to the \fBregex\fP manual page.
+.P
+.RE
+If a post-processing action (\fB-S\fP/\fB-I\fP/\fB-E\fP) results in an
+empty or a word containing only spaces, then we have two cases:
+.RS
+.IP "in column mode:"
+Substitutions involving empty words can lead to misalignments, so it is
+necessary to prohibit them and terminate the program.
+These substitutions have to be made with other tools before using this
+utility.
+.IP "otherwise:"
+The word is simply removed.
 .RE
 .IP "\fB-A\fP \fIregex\fP"
 In column mode, forces all words matching the given regular expression