[cros] Fix udevadm command line for camera presence detection.

Also added an overload of GetAppOutput which takes argv directly instead of CommandLine for launching programs where specific order of argument matters (like udevadm).

BUG=124845
TEST=Manual


Review URL: http://codereview.chromium.org/10191019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@134149 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 23 insertions, 14 deletions

diff --git a/base/process_util.h b/base/process_util.h
index f2e53cb..15d6b68 100644
--- a/base/process_util.h
+++ b/base/process_util.h
@@ -422,6 +422,12 @@ BASE_EXPORT bool SetJobObjectAsKillOnJobClose(HANDLE job_object);
 BASE_EXPORT bool GetAppOutput(const CommandLine& cl, std::string* output);
 
 #if defined(OS_POSIX)
+// A POSIX-specific version of GetAppOutput that takes an argv array
+// instead of a CommandLine.  Useful for situations where you need to
+// control the command line arguments directly.
+BASE_EXPORT bool GetAppOutput(const std::vector<std::string>& argv,
+                              std::string* output);
+
 // A restricted version of |GetAppOutput()| which (a) clears the environment,
 // and (b) stores at most |max_output| bytes; also, it doesn't search the path
 // for the command.
diff --git a/base/process_util_posix.cc b/base/process_util_posix.cc
index a86b935..77b096d 100644
--- a/base/process_util_posix.cc
+++ b/base/process_util_posix.cc
@@ -1048,10 +1048,10 @@ enum GetAppOutputInternalResult {
   GOT_MAX_OUTPUT,
 };
 
-// Executes the application specified by |cl| and wait for it to exit. Stores
+// Executes the application specified by |argv| and wait for it to exit. Stores
 // the output (stdout) in |output|. If |do_search_path| is set, it searches the
 // path for the application; in that case, |envp| must be null, and it will use
-// the current environment. If |do_search_path| is false, |cl| should fully
+// the current environment. If |do_search_path| is false, |argv[0]| should fully
 // specify the path of the application, and |envp| will be used as the
 // environment. Redirects stderr to /dev/null.
 // If we successfully start the application and get all requested output, we
@@ -1063,12 +1063,13 @@ enum GetAppOutputInternalResult {
 // In the case of EXECUTE_SUCCESS, the application exit code will be returned
 // in |*exit_code|, which should be checked to determine if the application
 // ran successfully.
-static GetAppOutputInternalResult GetAppOutputInternal(const CommandLine& cl,
-                                                       char* const envp[],
-                                                       std::string* output,
-                                                       size_t max_output,
-                                                       bool do_search_path,
-                                                       int* exit_code) {
+static GetAppOutputInternalResult GetAppOutputInternal(
+    const std::vector<std::string>& argv,
+    char* const envp[],
+    std::string* output,
+    size_t max_output,
+    bool do_search_path,
+    int* exit_code) {
   // Doing a blocking wait for another command to finish counts as IO.
   base::ThreadRestrictions::AssertIOAllowed();
   // exit_code must be supplied so calling function can determine success.
@@ -1078,7 +1079,6 @@ static GetAppOutputInternalResult GetAppOutputInternal(const CommandLine& cl,
   int pipe_fd[2];
   pid_t pid;
   InjectiveMultimap fd_shuffle1, fd_shuffle2;
-  const std::vector<std::string>& argv = cl.argv();
   scoped_array<char*> argv_cstr(new char*[argv.size() + 1]);
 
   fd_shuffle1.reserve(3);
@@ -1175,10 +1175,14 @@ static GetAppOutputInternalResult GetAppOutputInternal(const CommandLine& cl,
 }
 
 bool GetAppOutput(const CommandLine& cl, std::string* output) {
+  return GetAppOutput(cl.argv(), output);
+}
+
+bool GetAppOutput(const std::vector<std::string>& argv, std::string* output) {
   // Run |execve()| with the current environment and store "unlimited" data.
   int exit_code;
   GetAppOutputInternalResult result = GetAppOutputInternal(
-      cl, NULL, output, std::numeric_limits<std::size_t>::max(), true,
+      argv, NULL, output, std::numeric_limits<std::size_t>::max(), true,
       &exit_code);
   return result == EXECUTE_SUCCESS && exit_code == EXIT_SUCCESS;
 }
@@ -1190,9 +1194,8 @@ bool GetAppOutputRestricted(const CommandLine& cl,
   // Run |execve()| with the empty environment.
   char* const empty_environ = NULL;
   int exit_code;
-  GetAppOutputInternalResult result = GetAppOutputInternal(cl, &empty_environ,
-                                                           output, max_output,
-                                                           false, &exit_code);
+  GetAppOutputInternalResult result = GetAppOutputInternal(
+      cl.argv(), &empty_environ, output, max_output, false, &exit_code);
   return result == GOT_MAX_OUTPUT || (result == EXECUTE_SUCCESS &&
                                       exit_code == EXIT_SUCCESS);
 }
@@ -1202,7 +1205,7 @@ bool GetAppOutputWithExitCode(const CommandLine& cl,
                               int* exit_code) {
   // Run |execve()| with the current environment and store "unlimited" data.
   GetAppOutputInternalResult result = GetAppOutputInternal(
-      cl, NULL, output, std::numeric_limits<std::size_t>::max(), true,
+      cl.argv(), NULL, output, std::numeric_limits<std::size_t>::max(), true,
       exit_code);
   return result == EXECUTE_SUCCESS;
 }