+/*
+ * Crop and trim unit 'content' of 'length'. Return the new length.
+ */
+static size_t crop_and_trim_unit_content(char *content, size_t length)
+{
+ int st;
+ char c, *read, *write;
+
+ /* removes any comment and join continued lines */
+ st = 0;
+ read = write = content;
+ for (;;) {
+ do { c = *read++; } while (c == '\r');
+ if (!c)
+ break;
+ switch (st) {
+ case 0:
+ /* state 0: begin of a line */
+ if (c == ';' || c == '#') {
+ st = 3; /* removes lines starting with ; or # */
+ break;
+ }
+ if (c == '\n')
+ break; /* removes empty lines */
+enter_state_1:
+ st = 1;
+ /*@fallthrough@*/
+ case 1:
+ /* state 1: emitting a normal line */
+ if (c == '\\')
+ st = 2;
+ else {
+ *write++ = c;
+ if (c == '\n')
+ st = 0;
+ }
+ break;
+ case 2:
+ /* state 2: character after '\' */
+ if (c == '\n')
+ c = ' ';
+ else
+ *write++ = '\\';
+ goto enter_state_1;
+ case 3:
+ /* state 3: inside a comment, wait its end */
+ if (c == '\n')
+ st = 0;
+ break;
+ }
+ }
+ if (st == 1)
+ *write++ = '\n';
+ *write = 0;
+ return (size_t)(write - content);
+}
+
+/*
+ * read a unit file
+ */
+static int read_unit_file(const char *path, char **content, size_t *length)
+{
+ int rc;
+ size_t nl;
+
+ /* read the file */
+ rc = getfile(path, content, length);
+ if (rc >= 0) {
+ /* crop and trim it */
+ *length = nl = crop_and_trim_unit_content(*content, *length);
+ *content = realloc(*content, nl + 1);
+ }
+ return rc;
+}
+