Improve commenting/exit handling in binscripts

1 files changed, 13 insertions, 0 deletions

diff --git a/bin/u2d b/bin/u2d
index 662876e3..505b3d04 100755
--- a/bin/u2d
+++ b/bin/u2d
@@ -1,14 +1,27 @@
 #!/bin/sh
+# Convert UNIX line endings to DOS ones
+
+# Check arguments
 if [ "$#" -eq 0 ] ; then
     printf >&2 'u2d: Need a filename\n'
     exit 2
 fi
+
+# Put a carriage return into a variable for convenience
 r=$(printf '\r')
+
+# Iterate over arguments and apply the same ed(1) script to each of them
 for fn ; do
+
+    # Note the heredoc WORD is intentionally unquoted because we want to expand
+    # $r within it to get a literal carriage return; the escape characters
+    # prescribed for ed(1) by POSIX are very limited
     ed -s -- "$fn" <<EOF || ex=1
 g/[^$r]\$/ s/\$/$r/
 g/^\$/ s/\$/$r/
 w
 EOF
 done
+
+# If any of the ed(1) commands failed, we should exit with 1
 exit "${ex:-0}"