Apply runtime shebanging to POSIX shell

1 files changed, 25 insertions, 0 deletions

diff --git a/bin/d2u.sh b/bin/d2u.sh
new file mode 100644
index 00000000..22c8e16b
--- /dev/null
+++ b/bin/d2u.sh
@@ -0,0 +1,25 @@
+# Convert DOS line endings to UNIX ones
+
+# Check arguments
+if [ "$#" -eq 0 ] ; then
+    printf >&2 'd2u: Need a filename\n'
+    exit 2
+fi
+
+# Put a carriage return into a variable for convenience
+r=$(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\$//
+w
+EOF
+done
+
+# If any of the ed(1) commands failed, we should exit with 1
+exit "${ex:-0}"