From 91ff15fb954b3cee51384a72c9771149f256719b Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 7 Jan 2014 17:30:57 +0000
Subject: [PATCH] mllib: Add library function to run external command and slurp
 up the output.

This also changes a couple of functions to use this new library
function.

(cherry picked from commit a403febb8c43bf573c2354c39df22a29cf8863d8)
---
 builder/downloader.ml | 19 ++++---------------
 mllib/common_utils.ml | 16 +++++++++++++---
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/builder/downloader.ml b/builder/downloader.ml
index 442a011..77f48ae 100644
--- a/builder/downloader.ml
+++ b/builder/downloader.ml
@@ -75,23 +75,12 @@ and download_to ~prog t ?(progress_bar = false) uri filename =
     (if t.debug then "" else " -s -S")
     (quote uri) in
   if t.debug then eprintf "%s\n%!" cmd;
-  let chan = open_process_in cmd in
-  let status_code = input_line chan in
-  let stat = close_process_in chan in
-  (match stat with
-  | WEXITED 0 -> ()
-  | WEXITED i ->
-    eprintf (f_"virt-builder: curl (download) command failed downloading '%s'\n") uri;
-    exit 1
-  | WSIGNALED i ->
-    eprintf (f_"virt-builder: external command '%s' killed by signal %d\n")
-      cmd i;
-    exit 1
-  | WSTOPPED i ->
-    eprintf (f_"virt-builder: external command '%s' stopped by signal %d\n")
-      cmd i;
+  let lines = external_command ~prog cmd in
+  if List.length lines < 1 then (
+    eprintf (f_"%s: unexpected output from curl command, enable debug and look at previous messages\n") prog;
     exit 1
   );
+  let status_code = List.hd lines in
   let bad_status_code = function
     | "" -> true
     | s when s.[0] = '4' -> true (* 4xx *)
diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml
index 80c5aca..3943417 100644
--- a/mllib/common_utils.ml
+++ b/mllib/common_utils.ml
@@ -332,10 +332,13 @@ let display_long_options () =
   ) !long_options;
   exit 0
 
-let uuidgen ~prog () =
-  let cmd = "uuidgen -r" in
+(* Run an external command, slurp up the output as a list of lines. *)
+let external_command ~prog cmd =
   let chan = Unix.open_process_in cmd in
-  let uuid = input_line chan in
+  let lines = ref [] in
+  (try while true do lines := input_line chan :: !lines done
+   with End_of_file -> ());
+  let lines = List.rev !lines in
   let stat = Unix.close_process_in chan in
   (match stat with
   | Unix.WEXITED 0 -> ()
@@ -346,6 +349,13 @@ let uuidgen ~prog () =
   | Unix.WSTOPPED i ->
     error ~prog (f_"external command '%s' stopped by signal %d") cmd i
   );
+  lines
+
+(* Run uuidgen to return a random UUID. *)
+let uuidgen ~prog () =
+  let lines = external_command ~prog "uuidgen -r" in
+  assert (List.length lines >= 1);
+  let uuid = List.hd lines in
   let len = String.length uuid in
   let uuid, len =
     if len > 0 && uuid.[len-1] = '\n' then
-- 
1.8.4.2