From 74ed34b4a34704e451a7c889058653185ccd9527 Mon Sep 17 00:00:00 2001
From: Alex Shinn <alexshinn@gmail.com>
Date: Fri, 24 Apr 2015 14:10:13 +0900
Subject: [PATCH] Adding a system? variant of system which returns #t iff the
 command completes successfully. Also allowing a list as the first argument to
 both.

---
 lib/chibi/process.scm | 9 +++++++--
 lib/chibi/process.sld | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/chibi/process.scm b/lib/chibi/process.scm
index 0d4c0d4f..cdb14af7 100644
--- a/lib/chibi/process.scm
+++ b/lib/chibi/process.scm
@@ -68,11 +68,16 @@
   (let ((pid (fork)))
     (cond
      ((zero? pid)
-      (execute cmd (cons cmd args))
-      (execute-returned cmd))
+      (let ((cmd ((if (pair? cmd) append cons) cmd args)))
+        (execute (car cmd) cmd)
+        (execute-returned cmd)))
      (else
       (waitpid pid 0)))))
 
+(define (system? cmd . args)
+  (let ((res (apply system cmd args)))
+    (and (pair? res) (zero? (cadr res)))))
+
 (define (call-with-process-io command proc)
   (define (set-non-blocking! fd)
     (cond-expand
diff --git a/lib/chibi/process.sld b/lib/chibi/process.sld
index 84b58cb4..40d9849d 100644
--- a/lib/chibi/process.sld
+++ b/lib/chibi/process.sld
@@ -1,6 +1,6 @@
 
 (define-library (chibi process)
-  (export exit sleep alarm %fork fork kill execute waitpid system
+  (export exit sleep alarm %fork fork kill execute waitpid system system?
           process-command-line  process-running?
           set-signal-action! make-signal-set
           signal-set? signal-set-contains?