More strbuf helper functions

strbuf_append_argv()

strbuf_path_join()

log.c

@@ -235,15 +235,7 @@ void logArgv(int level, struct __sourceloc whence, const char *label, int argc,
       strbuf_puts(&logbuf, label);
       strbuf_putc(&logbuf, ' ');
     }
-    int i;
+    strbuf_append_argv(&logbuf, argc, argv);
-    for (i = 0; i < argc; ++i) {
-      if (i)
-	strbuf_putc(&logbuf, ' ');
-      if (argv[i])
-	strbuf_toprint_quoted(&logbuf, "\"\"", argv[i]);
-      else
-	strbuf_puts(&logbuf, "NULL");
-    }
     _log_finish(level);
   }
 }

strbuf_helpers.c

@@ -21,6 +21,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <poll.h>
 #include <ctype.h>
 #include <string.h>
+#include <stdarg.h>
 #include <sys/wait.h>
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
@@ -112,6 +113,22 @@ strbuf strbuf_toprint_quoted(strbuf sb, const char quotes[2], const char *str)
   return _overrun_quote(sb, quotes ? quotes[1] : '\0', "...");
 }
 
+strbuf strbuf_path_join(strbuf sb, ...)
+{
+  va_list ap;
+  va_start(ap, sb);
+  const char *segment;
+  while ((segment = va_arg(ap, const char*))) {
+    if (segment[0] == '/')
+      strbuf_reset(sb);
+    else if (strbuf_len(sb) && *strbuf_substr(sb, -1) != '/')
+      strbuf_putc(sb, '/');
+    strbuf_puts(sb, segment);
+  }
+  va_end(ap);
+  return sb;
+}
+
 strbuf strbuf_append_poll_events(strbuf sb, short events)
 {
   static struct { short flags; const char *name; } symbols[] = {
@@ -186,6 +203,20 @@ strbuf strbuf_append_shell_quotemeta(strbuf sb, const char *word)
   return sb;
 }
 
+strbuf strbuf_append_argv(strbuf sb, int argc, const char *const *argv)
+{
+  int i;
+  for (i = 0; i < argc; ++i) {
+    if (i)
+      strbuf_putc(sb, ' ');
+    if (argv[i])
+      strbuf_toprint_quoted(sb, "\"\"", argv[i]);
+    else
+      strbuf_puts(sb, "NULL");
+  }
+  return sb;
+}
+
 strbuf strbuf_append_exit_status(strbuf sb, int status)
 {
   if (WIFEXITED(status))

strbuf_helpers.h

@@ -46,6 +46,14 @@ strbuf strbuf_toprint_quoted_len(strbuf sb, const char quotes[2], const char *bu
  */
 strbuf strbuf_toprint_quoted(strbuf sb, const char quotes[2], const char *str);
 
+/* Join Unix file path segments together with separator characters '/' to form
+ * a complete path.  Any segment that starts with '/' is taken as the start of
+ * an absolute path, and all prior segments are discarded.
+ *
+ * @author Andrew Bettison <andrew@servalproject.com>
+ */
+strbuf strbuf_path_join(strbuf sb, ...);
+
 /* Append a symbolic representation of the poll(2) event flags.
  * @author Andrew Bettison <andrew@servalproject.com>
  */
@@ -74,6 +82,13 @@ strbuf strbuf_append_shell_quote(strbuf sb, const char *word);
  */
 strbuf strbuf_append_shell_quotemeta(strbuf sb, const char *word);
 
+/* Append an array of nul-terminated strings as a space-separated sequence of
+ * quoted strings.  Any NULL entry in argv[] is printed as unquoted "NULL".
+ *
+ * @author Andrew Bettison <andrew@servalproject.com>
+ */
+strbuf strbuf_append_argv(strbuf sb, int argc, const char *const *argv);
+
 /* Append a textual description of a process exit status as produced by wait(2)
  * and waitpid(2).
  * @author Andrew Bettison <andrew@servalproject.com>