Prevent matching illegal sequences globally

E.g., a+b will no longer be matched by anything.  This is due to the
global usage of a modified list_all().

Also:
- Use different return types for different things (e.g. $RET_SUCCESS).
 `- Both internally and externally (exit codes, documented in ctct(1)).
- Make --search-by-data more efficient.
 `- One call to grep for all files.
 `- The conjunction of the regexes still requires several calls.
- Rename functions to more speaking names.
- Document the function parameters.
- Add vi modelines.
- Use [[:alpha:]] instead of [A-Za-z] which appears to be the same but
  more clear.  Notably, both seem to include non-ASCII letters, for
  example 'à'.
- Set nullglob option in the script to prevent errors for cases where
  glob patterns would be used.
- Add a silent option ro check_syntax() (not used).
- Add a full_path option to list_all() (not used).
- Use return instead of exit in main().
- Remove one remaining usage of eval.
- Fix small format issue in ctct(1) (I -> B).
 `- They are no longer, but it hardly harms to have this option.

1 files changed, 15 insertions, 0 deletions

diff --git a/configure b/configure
index b3b2ca9..35c1039 100755
--- a/configure
+++ b/configure
@@ -595,6 +595,10 @@ default_fallback_editor
 default_datadir
 sysconfdir_expanded
 bash_completion_dir
+ret_error
+ret_badsyntax
+ret_failure
+ret_success
 target_alias
 host_alias
 build_alias
@@ -1710,6 +1714,17 @@ ac_config_files="$ac_config_files ctct"
 
 
 
+# ret_success must be 0, all others nonzero.
+ret_success=0
+
+ret_failure=1
+
+ret_badsyntax=2
+
+ret_error=4
+
+
+
 
 test -z "$bash_completion_dir" \
 	&& bash_completion_dir='${datarootdir}/bash-completion/completions'