Fix various adb error reporting bugs.

`adb install` was writing success to stderr rather than stdout.

Server mismatch messages were going to stdout rather than stderr.

Error messages should consistently start with a lower case letter.

Also improve consistency of syntax error reporting.

Bug: https://issuetracker.google.com/37128706 (adb install success to stdout)
Bug: https://issuetracker.google.com/37140458 (server mismatch on stderr)
Bug: http://b/32413861 (consistency)
Test: ran tests
Change-Id: I0d6cb0c7482bec03483dacefd996644b7a28d273

7 files changed, 103 insertions, 132 deletions

diff --git a/adb.cpp b/adb.cpp
index cf6b359..51d5876 100644
--- a/adb.cpp
+++ b/adb.cpp
@@ -507,8 +507,8 @@ static bool _make_handle_noninheritable(HANDLE h) {
     if (!_try_make_handle_noninheritable(h)) {
         // Show the handle value to give us a clue in case we have problems
         // with pseudo-handle values.
-        fprintf(stderr, "Cannot make handle 0x%p non-inheritable: %s\n",
-                h, android::base::SystemErrorCodeToString(GetLastError()).c_str());
+        fprintf(stderr, "adb: cannot make handle 0x%p non-inheritable: %s\n", h,
+                android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return false;
     }
 
@@ -523,7 +523,7 @@ static bool _create_anonymous_pipe(unique_handle* pipe_read_out,
     HANDLE pipe_read_raw = NULL;
     HANDLE pipe_write_raw = NULL;
     if (!CreatePipe(&pipe_read_raw, &pipe_write_raw, sa, 0)) {
-        fprintf(stderr, "Cannot create pipe: %s\n",
+        fprintf(stderr, "adb: CreatePipe failed: %s\n",
                 android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return false;
     }
@@ -554,7 +554,8 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
     std::unique_ptr<FILE, decltype(&fclose)> stream(nullptr, fclose);
 
     if (original_fd == -1) {
-        fprintf(stderr, "Failed to get file descriptor for %s: %s\n", output_name, strerror(errno));
+        fprintf(stderr, "adb: failed to get file descriptor for %s: %s\n", output_name,
+                strerror(errno));
         return EXIT_FAILURE;
     }
 
@@ -566,7 +567,7 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
         // call this function if subprocesses may be started concurrently.
         const int fd = dup(original_fd);
         if (fd == -1) {
-            fprintf(stderr, "Failed to duplicate file descriptor for %s: %s\n", output_name,
+            fprintf(stderr, "adb: failed to duplicate file descriptor for %s: %s\n", output_name,
                     strerror(errno));
             return EXIT_FAILURE;
         }
@@ -574,7 +575,7 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
         // Note that although we call fdopen() below with a binary flag, it may not adhere to that
         // flag, so we have to set the mode manually.
         if (_setmode(fd, _O_BINARY) == -1) {
-            fprintf(stderr, "Failed to set binary mode for duplicate of %s: %s\n", output_name,
+            fprintf(stderr, "adb: failed to set binary mode for duplicate of %s: %s\n", output_name,
                     strerror(errno));
             unix_close(fd);
             return EXIT_FAILURE;
@@ -582,7 +583,7 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
 
         stream.reset(fdopen(fd, "wb"));
         if (stream.get() == nullptr) {
-            fprintf(stderr, "Failed to open duplicate stream for %s: %s\n", output_name,
+            fprintf(stderr, "adb: failed to open duplicate stream for %s: %s\n", output_name,
                     strerror(errno));
             unix_close(fd);
             return EXIT_FAILURE;
@@ -591,7 +592,7 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
         // Unbuffer the stream because it will be buffered by default and we want subprocess output
         // to be shown immediately.
         if (setvbuf(stream.get(), NULL, _IONBF, 0) == -1) {
-            fprintf(stderr, "Failed to unbuffer %s: %s\n", output_name, strerror(errno));
+            fprintf(stderr, "adb: failed to unbuffer %s: %s\n", output_name, strerror(errno));
             return EXIT_FAILURE;
         }
 
@@ -608,7 +609,7 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
             if (err == ERROR_BROKEN_PIPE) {
                 return EXIT_SUCCESS;
             } else {
-                fprintf(stderr, "Failed to read from %s: %s\n", output_name,
+                fprintf(stderr, "adb: failed to read from %s: %s\n", output_name,
                         android::base::SystemErrorCodeToString(err).c_str());
                 return EXIT_FAILURE;
             }
@@ -619,8 +620,8 @@ static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
             // fwrite() actually calls adb_fwrite() which can write UTF-8 to the console.
             const size_t bytes_written = fwrite(buf, 1, bytes_read, stream.get());
             if (bytes_written != bytes_read) {
-                fprintf(stderr, "Only wrote %zu of %lu bytes to %s\n", bytes_written, bytes_read,
-                        output_name);
+                fprintf(stderr, "adb: error: only wrote %zu of %lu bytes to %s\n", bytes_written,
+                        bytes_read, output_name);
                 return EXIT_FAILURE;
             }
         }
@@ -663,7 +664,7 @@ int launch_server(const std::string& socket_spec) {
             FILE_SHARE_READ | FILE_SHARE_WRITE, &sa, OPEN_EXISTING,
             FILE_ATTRIBUTE_NORMAL, NULL));
     if (nul_read.get() == INVALID_HANDLE_VALUE) {
-        fprintf(stderr, "Cannot open 'nul': %s\n",
+        fprintf(stderr, "adb: CreateFileW 'nul' failed: %s\n",
                 android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return -1;
     }
@@ -725,8 +726,7 @@ int launch_server(const std::string& socket_spec) {
         // If this fires, either handle values are larger than 32-bits or else
         // there is a bug in our casting.
         // https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203%28v=vs.85%29.aspx
-        fprintf(stderr, "Cannot fit pipe handle value into 32-bits: 0x%p\n",
-                ack_write.get());
+        fprintf(stderr, "adb: cannot fit pipe handle value into 32-bits: 0x%p\n", ack_write.get());
         return -1;
     }
 
@@ -736,7 +736,7 @@ int launch_server(const std::string& socket_spec) {
                                                    arraysize(program_path));
     if ((module_result >= arraysize(program_path)) || (module_result == 0)) {
         // String truncation or some other error.
-        fprintf(stderr, "Cannot get executable path: %s\n",
+        fprintf(stderr, "adb: cannot get executable path: %s\n",
                 android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return -1;
     }
@@ -761,7 +761,7 @@ int launch_server(const std::string& socket_spec) {
             NULL,                    /* use parent's starting directory */
             &startup,                 /* startup info, i.e. std handles */
             &pinfo )) {
-        fprintf(stderr, "Cannot create process: %s\n",
+        fprintf(stderr, "adb: CreateProcessW failed: %s\n",
                 android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return -1;
     }
@@ -791,7 +791,7 @@ int launch_server(const std::string& socket_spec) {
             _beginthreadex(NULL, 0, _redirect_stdout_thread, stdout_read.get(),
                            0, NULL)));
     if (stdout_thread.get() == nullptr) {
-        fprintf(stderr, "Cannot create thread: %s\n", strerror(errno));
+        fprintf(stderr, "adb: cannot create thread: %s\n", strerror(errno));
         return -1;
     }
     stdout_read.release();  // Transfer ownership to new thread
@@ -800,7 +800,7 @@ int launch_server(const std::string& socket_spec) {
             _beginthreadex(NULL, 0, _redirect_stderr_thread, stderr_read.get(),
                            0, NULL)));
     if (stderr_thread.get() == nullptr) {
-        fprintf(stderr, "Cannot create thread: %s\n", strerror(errno));
+        fprintf(stderr, "adb: cannot create thread: %s\n", strerror(errno));
         return -1;
     }
     stderr_read.release();  // Transfer ownership to new thread
@@ -845,22 +845,20 @@ int launch_server(const std::string& socket_spec) {
     if (wait_result == WAIT_TIMEOUT) {
         // Threads did not finish after waiting a little while. Perhaps the
         // server didn't close pipes, or it is hung.
-        fprintf(stderr, "Timed-out waiting for threads to finish reading from "
-                "ADB Server\n");
+        fprintf(stderr, "adb: timed out waiting for threads to finish reading from ADB server\n");
         // Process handles are signaled when the process exits, so if we wait
         // on the handle for 0 seconds and it returns 'timeout', that means that
         // the process is still running.
         if (WaitForSingleObject(process_handle.get(), 0) == WAIT_TIMEOUT) {
             // We could TerminateProcess(), but that seems somewhat presumptive.
-            fprintf(stderr, "ADB Server is running: process id %lu\n",
-                    pinfo.dwProcessId);
+            fprintf(stderr, "adb: server is running with process id %lu\n", pinfo.dwProcessId);
         }
         return -1;
     }
 
     if (wait_result != WAIT_OBJECT_0) {
-        fprintf(stderr, "Unexpected result waiting for threads: %lu: %s\n",
-                wait_result, android::base::SystemErrorCodeToString(GetLastError()).c_str());
+        fprintf(stderr, "adb: unexpected result waiting for threads: %lu: %s\n", wait_result,
+                android::base::SystemErrorCodeToString(GetLastError()).c_str());
         return -1;
     }
 
@@ -894,7 +892,7 @@ int launch_server(const std::string& socket_spec) {
         int result = execl(path.c_str(), "adb", "-L", socket_spec.c_str(), "fork-server", "server",
                            "--reply-fd", reply_fd, NULL);
         // this should not return
-        fprintf(stderr, "OOPS! execl returned %d, errno: %d\n", result, errno);
+        fprintf(stderr, "adb: execl returned %d: %s\n", result, strerror(errno));
     } else  {
         // parent side of the fork
 
diff --git a/adb_client.cpp b/adb_client.cpp
index ef52189..b2b5c0e 100644
--- a/adb_client.cpp
+++ b/adb_client.cpp
@@ -164,21 +164,21 @@ int adb_connect(const std::string& service, std::string* error) {
 
     D("adb_connect: service %s", service.c_str());
     if (fd == -2 && !is_local_socket_spec(__adb_server_socket_spec)) {
-        fprintf(stderr,"** Cannot start server on remote host\n");
+        fprintf(stderr, "* cannot start server on remote host\n");
         // error is the original network connection error
         return fd;
     } else if (fd == -2) {
-        fprintf(stdout, "* daemon not running. starting it now at %s *\n", __adb_server_socket_spec);
+        fprintf(stderr, "* daemon not running; starting now at %s\n", __adb_server_socket_spec);
     start_server:
         if (launch_server(__adb_server_socket_spec)) {
-            fprintf(stderr,"* failed to start daemon *\n");
+            fprintf(stderr, "* failed to start daemon\n");
             // launch_server() has already printed detailed error info, so just
             // return a generic error string about the overall adb_connect()
             // that the caller requested.
             *error = "cannot connect to daemon";
             return -1;
         } else {
-            fprintf(stdout,"* daemon started successfully *\n");
+            fprintf(stderr, "* daemon started successfully\n");
         }
         // Give the server some time to start properly and detect devices.
         std::this_thread::sleep_for(3s);
@@ -213,8 +213,8 @@ int adb_connect(const std::string& service, std::string* error) {
         }
 
         if (version != ADB_SERVER_VERSION) {
-            printf("adb server version (%d) doesn't match this client (%d); killing...\n",
-                   version, ADB_SERVER_VERSION);
+            fprintf(stderr, "adb server version (%d) doesn't match this client (%d); killing...\n",
+                    version, ADB_SERVER_VERSION);
             fd = _adb_connect("host:kill", error);
             if (fd >= 0) {
                 ReadOrderlyShutdown(fd);
@@ -240,7 +240,7 @@ int adb_connect(const std::string& service, std::string* error) {
     if (fd == -1) {
         D("_adb_connect error: %s", error->c_str());
     } else if(fd == -2) {
-        fprintf(stderr,"** daemon still not running\n");
+        fprintf(stderr, "* daemon still not running\n");
     }
     D("adb_connect: return fd %d", fd);
 
diff --git a/adb_utils.cpp b/adb_utils.cpp
index 31d3dc6..6f2403d 100644
--- a/adb_utils.cpp
+++ b/adb_utils.cpp
@@ -267,8 +267,8 @@ void AdbCloser::Close(int fd) {
     adb_close(fd);
 }
 
-int usage(const char* fmt, ...) {
-    fprintf(stderr, "adb: ");
+int syntax_error(const char* fmt, ...) {
+    fprintf(stderr, "adb: usage: ");
 
     va_list ap;
     va_start(ap, fmt);
diff --git a/adb_utils.h b/adb_utils.h
index e0ad103..c1d5549 100644
--- a/adb_utils.h
+++ b/adb_utils.h
@@ -21,7 +21,7 @@
 
 #include <android-base/macros.h>
 
-int usage(const char*, ...);
+int syntax_error(const char*, ...);
 
 void close_stdin();
 
diff --git a/bugreport.cpp b/bugreport.cpp
index 9dc9811..da2cfa2 100644
--- a/bugreport.cpp
+++ b/bugreport.cpp
@@ -137,7 +137,7 @@ class BugreportStandardStreamsCallback : public StandardStreamsCallbackInterface
             SetSrcFile(&line[strlen(BUGZ_OK_PREFIX)]);
         } else if (android::base::StartsWith(line, BUGZ_FAIL_PREFIX)) {
             const char* error_message = &line[strlen(BUGZ_FAIL_PREFIX)];
-            fprintf(stderr, "Device failed to take a zipped bugreport: %s\n", error_message);
+            fprintf(stderr, "adb: device failed to take a zipped bugreport: %s\n", error_message);
             status_ = -1;
         } else if (show_progress_ && android::base::StartsWith(line, BUGZ_PROGRESS_PREFIX)) {
             // progress_line should have the following format:
@@ -195,7 +195,7 @@ class BugreportStandardStreamsCallback : public StandardStreamsCallbackInterface
 };
 
 int Bugreport::DoIt(TransportType transport_type, const char* serial, int argc, const char** argv) {
-    if (argc > 2) return usage("usage: adb bugreport [PATH]");
+    if (argc > 2) return syntax_error("adb bugreport [PATH]");
 
     // Gets bugreportz version.
     std::string bugz_stdout, bugz_stderr;
diff --git a/commandline.cpp b/commandline.cpp
index 7702b0e..d626259 100644
--- a/commandline.cpp
+++ b/commandline.cpp
@@ -690,8 +690,7 @@ static int adb_shell(int argc, const char** argv) {
         switch (opt) {
             case 'e':
                 if (!(strlen(optarg) == 1 || strcmp(optarg, "none") == 0)) {
-                    fprintf(stderr, "error: -e requires a single-character argument or 'none'\n");
-                    return 1;
+                    return syntax_error("-e requires a single-character argument or 'none'");
                 }
                 escape_char = (strcmp(optarg, "none") == 0) ? 0 : optarg[0];
                 break;
@@ -843,7 +842,10 @@ static int adb_download_buffer(const char* service, const char* filename) {
  *   we hang up.
  */
 static int adb_sideload_host(const char* filename) {
-    fprintf(stderr, "opening '%s'...\n", filename);
+    // TODO: use a LinePrinter instead...
+    fprintf(stdout, "opening '%s'...\n", filename);
+    fflush(stdout);
+
     struct stat sb;
     if (stat(filename, &sb) == -1) {
         fprintf(stderr, "failed to stat file %s: %s\n", filename, strerror(errno));
@@ -855,7 +857,8 @@ static int adb_sideload_host(const char* filename) {
         return -1;
     }
 
-    fprintf(stderr, "connecting...\n");
+    fprintf(stdout, "connecting...\n");
+    fflush(stdout);
     std::string service = android::base::StringPrintf(
         "sideload-host:%d:%d", static_cast<int>(sb.st_size), SIDELOAD_HOST_BLOCK_SIZE);
     std::string error;
@@ -944,19 +947,13 @@ static int ppp(int argc, const char** argv) {
     fprintf(stderr, "error: adb %s not implemented on Win32\n", argv[0]);
     return -1;
 #else
-    if (argc < 2) {
-        fprintf(stderr, "usage: adb %s <adb service name> [ppp opts]\n",
-                argv[0]);
-
-        return 1;
-    }
+    if (argc < 2) return syntax_error("adb %s <adb service name> [ppp opts]", argv[0]);
 
     const char* adb_service_name = argv[1];
     std::string error;
     int fd = adb_connect(adb_service_name, &error);
     if (fd < 0) {
-        fprintf(stderr,"Error: Could not open adb service: %s. Error: %s\n",
-                adb_service_name, error.c_str());
+        fprintf(stderr, "adb: could not open adb service %s: %s\n", adb_service_name, error.c_str());
         return 1;
     }
 
@@ -1175,10 +1172,7 @@ static int backup(int argc, const char** argv) {
     /* find, extract, and use any -f argument */
     for (int i = 1; i < argc; i++) {
         if (!strcmp("-f", argv[i])) {
-            if (i == argc-1) {
-                fprintf(stderr, "adb: backup -f passed with no filename.\n");
-                return EXIT_FAILURE;
-            }
+            if (i == argc - 1) return syntax_error("backup -f passed with no filename");
             filename = argv[i+1];
             for (int j = i+2; j <= argc; ) {
                 argv[i++] = argv[j++];
@@ -1190,10 +1184,7 @@ static int backup(int argc, const char** argv) {
 
     // Bare "adb backup" or "adb backup -f filename" are not valid invocations ---
     // a list of packages is required.
-    if (argc < 2) {
-        fprintf(stderr, "adb: backup either needs a list of packages or -all/-shared.\n");
-        return EXIT_FAILURE;
-    }
+    if (argc < 2) return syntax_error("backup either needs a list of packages or -all/-shared");
 
     adb_unlink(filename);
     int outFd = adb_creat(filename, 0640);
@@ -1218,7 +1209,7 @@ static int backup(int argc, const char** argv) {
         return EXIT_FAILURE;
     }
 
-    printf("Now unlock your device and confirm the backup operation...\n");
+    fprintf(stdout, "Now unlock your device and confirm the backup operation...\n");
     fflush(stdout);
 
     copy_to_file(fd, outFd);
@@ -1229,7 +1220,7 @@ static int backup(int argc, const char** argv) {
 }
 
 static int restore(int argc, const char** argv) {
-    if (argc != 2) return usage("restore requires an argument");
+    if (argc != 2) return syntax_error("restore requires an argument");
 
     const char* filename = argv[1];
     int tarFd = adb_open(filename, O_RDONLY);
@@ -1246,7 +1237,9 @@ static int restore(int argc, const char** argv) {
         return -1;
     }
 
-    printf("Now unlock your device and confirm the restore operation.\n");
+    fprintf(stdout, "Now unlock your device and confirm the restore operation.\n");
+    fflush(stdout);
+
     copy_to_file(tarFd, fd);
 
     // Provide an in-band EOD marker in case the archive file is malformed
@@ -1338,7 +1331,7 @@ static void parse_push_pull_args(const char** arg, int narg,
             } else if (!strcmp(*arg, "--")) {
                 ignore_flags = true;
             } else {
-                fprintf(stderr, "adb: unrecognized option '%s'\n", *arg);
+                syntax_error("unrecognized option '%s'", *arg);
                 exit(1);
             }
         }
@@ -1437,7 +1430,7 @@ int adb_commandline(int argc, const char** argv) {
             /* this is a special flag used only when the ADB client launches the ADB Server */
             is_daemon = 1;
         } else if (!strcmp(argv[0], "--reply-fd")) {
-            if (argc < 2) return usage("--reply-fd requires an argument");
+            if (argc < 2) return syntax_error("--reply-fd requires an argument");
             const char* reply_fd_str = argv[1];
             argc--;
             argv++;
@@ -1449,7 +1442,7 @@ int adb_commandline(int argc, const char** argv) {
         } else if (!strncmp(argv[0], "-p", 2)) {
             const char* product = nullptr;
             if (argv[0][2] == '\0') {
-                if (argc < 2) return usage("-p requires an argument");
+                if (argc < 2) return syntax_error("-p requires an argument");
                 product = argv[1];
                 argc--;
                 argv++;
@@ -1465,7 +1458,7 @@ int adb_commandline(int argc, const char** argv) {
             if (isdigit(argv[0][2])) {
                 serial = argv[0] + 2;
             } else {
-                if (argc < 2 || argv[0][2] != '\0') return usage("-s requires an argument");
+                if (argc < 2 || argv[0][2] != '\0') return syntax_error("-s requires an argument");
                 serial = argv[1];
                 argc--;
                 argv++;
@@ -1478,7 +1471,7 @@ int adb_commandline(int argc, const char** argv) {
             gListenAll = 1;
         } else if (!strncmp(argv[0], "-H", 2)) {
             if (argv[0][2] == '\0') {
-                if (argc < 2) return usage("-H requires an argument");
+                if (argc < 2) return syntax_error("-H requires an argument");
                 server_host_str = argv[1];
                 argc--;
                 argv++;
@@ -1487,7 +1480,7 @@ int adb_commandline(int argc, const char** argv) {
             }
         } else if (!strncmp(argv[0], "-P", 2)) {
             if (argv[0][2] == '\0') {
-                if (argc < 2) return usage("-P requires an argument");
+                if (argc < 2) return syntax_error("-P requires an argument");
                 server_port_str = argv[1];
                 argc--;
                 argv++;
@@ -1495,7 +1488,7 @@ int adb_commandline(int argc, const char** argv) {
                 server_port_str = argv[0] + 2;
             }
         } else if (!strcmp(argv[0], "-L")) {
-            if (argc < 2) return usage("-L requires an argument");
+            if (argc < 2) return syntax_error("-L requires an argument");
             server_socket_str = argv[1];
             argc--;
             argv++;
@@ -1508,8 +1501,7 @@ int adb_commandline(int argc, const char** argv) {
     }
 
     if ((server_host_str || server_port_str) && server_socket_str) {
-        fprintf(stderr, "adb: -L is incompatible with -H or -P\n");
-        exit(1);
+        return syntax_error("-L is incompatible with -H or -P");
     }
 
     // If -L, -H, or -P are specified, ignore environment variables.
@@ -1604,8 +1596,7 @@ int adb_commandline(int argc, const char** argv) {
         } else if (argc == 2 && !strcmp(argv[1], "-l")) {
             listopt = argv[1];
         } else {
-            fprintf(stderr, "Usage: adb devices [-l]\n");
-            return 1;
+            return syntax_error("adb devices [-l]");
         }
 
         std::string query = android::base::StringPrintf("host:%s%s", argv[0], listopt);
@@ -1613,19 +1604,13 @@ int adb_commandline(int argc, const char** argv) {
         return adb_query_command(query);
     }
     else if (!strcmp(argv[0], "connect")) {
-        if (argc != 2) {
-            fprintf(stderr, "Usage: adb connect <host>[:<port>]\n");
-            return 1;
-        }
+        if (argc != 2) return syntax_error("adb connect <host>[:<port>]");
 
         std::string query = android::base::StringPrintf("host:connect:%s", argv[1]);
         return adb_query_command(query);
     }
     else if (!strcmp(argv[0], "disconnect")) {
-        if (argc > 2) {
-            fprintf(stderr, "Usage: adb disconnect [<host>[:<port>]]\n");
-            return 1;
-        }
+        if (argc > 2) return syntax_error("adb disconnect [<host>[:<port>]]");
 
         std::string query = android::base::StringPrintf("host:disconnect:%s",
                                                         (argc == 2) ? argv[1] : "");
@@ -1640,10 +1625,7 @@ int adb_commandline(int argc, const char** argv) {
     else if (!strcmp(argv[0], "exec-in") || !strcmp(argv[0], "exec-out")) {
         int exec_in = !strcmp(argv[0], "exec-in");
 
-        if (argc < 2) {
-            fprintf(stderr, "Usage: adb %s command\n", argv[0]);
-            return 1;
-        }
+        if (argc < 2) return syntax_error("adb %s command", argv[0]);
 
         std::string cmd = "exec:";
         cmd += argv[1];
@@ -1691,7 +1673,7 @@ int adb_commandline(int argc, const char** argv) {
         }
     }
     else if (!strcmp(argv[0], "sideload")) {
-        if (argc != 2) return usage("sideload requires an argument");
+        if (argc != 2) return syntax_error("sideload requires an argument");
         if (adb_sideload_host(argv[1])) {
             return 1;
         } else {
@@ -1725,7 +1707,7 @@ int adb_commandline(int argc, const char** argv) {
         bool reverse = !strcmp(argv[0], "reverse");
         ++argv;
         --argc;
-        if (argc < 1) return usage("%s requires an argument", argv[0]);
+        if (argc < 1) return syntax_error("%s requires an argument", argv[0]);
 
         // Determine the <host-prefix> for this command.
         std::string host_prefix;
@@ -1745,24 +1727,24 @@ int adb_commandline(int argc, const char** argv) {
 
         std::string cmd, error;
         if (strcmp(argv[0], "--list") == 0) {
-            if (argc != 1) return usage("--list doesn't take any arguments");
+            if (argc != 1) return syntax_error("--list doesn't take any arguments");
             return adb_query_command(host_prefix + ":list-forward");
         } else if (strcmp(argv[0], "--remove-all") == 0) {
-            if (argc != 1) return usage("--remove-all doesn't take any arguments");
+            if (argc != 1) return syntax_error("--remove-all doesn't take any arguments");
             cmd = host_prefix + ":killforward-all";
         } else if (strcmp(argv[0], "--remove") == 0) {
             // forward --remove <local>
-            if (argc != 2) return usage("--remove requires an argument");
+            if (argc != 2) return syntax_error("--remove requires an argument");
             cmd = host_prefix + ":killforward:" + argv[1];
         } else if (strcmp(argv[0], "--no-rebind") == 0) {
             // forward --no-rebind <local> <remote>
-            if (argc != 3) return usage("--no-rebind takes two arguments");
+            if (argc != 3) return syntax_error("--no-rebind takes two arguments");
             if (forward_targets_are_valid(argv[1], argv[2], &error)) {
                 cmd = host_prefix + ":forward:norebind:" + argv[1] + ";" + argv[2];
             }
         } else {
             // forward <local> <remote>
-            if (argc != 2) return usage("forward takes two arguments");
+            if (argc != 2) return syntax_error("forward takes two arguments");
             if (forward_targets_are_valid(argv[0], argv[1], &error)) {
                 cmd = host_prefix + ":forward:" + argv[0] + ";" + argv[1];
             }
@@ -1791,7 +1773,7 @@ int adb_commandline(int argc, const char** argv) {
     }
     /* do_sync_*() commands */
     else if (!strcmp(argv[0], "ls")) {
-        if (argc != 2) return usage("ls requires an argument");
+        if (argc != 2) return syntax_error("ls requires an argument");
         return do_sync_ls(argv[1]) ? 0 : 1;
     }
     else if (!strcmp(argv[0], "push")) {
@@ -1800,7 +1782,7 @@ int adb_commandline(int argc, const char** argv) {
         const char* dst = nullptr;
 
         parse_push_pull_args(&argv[1], argc - 1, &srcs, &dst, &copy_attrs);
-        if (srcs.empty() || !dst) return usage("push requires an argument");
+        if (srcs.empty() || !dst) return syntax_error("push requires an argument");
         return do_sync_push(srcs, dst) ? 0 : 1;
     }
     else if (!strcmp(argv[0], "pull")) {
@@ -1809,22 +1791,22 @@ int adb_commandline(int argc, const char** argv) {
         const char* dst = ".";
 
         parse_push_pull_args(&argv[1], argc - 1, &srcs, &dst, &copy_attrs);
-        if (srcs.empty()) return usage("pull requires an argument");
+        if (srcs.empty()) return syntax_error("pull requires an argument");
         return do_sync_pull(srcs, dst, copy_attrs) ? 0 : 1;
     }
     else if (!strcmp(argv[0], "install")) {
-        if (argc < 2) return usage("install requires an argument");
+        if (argc < 2) return syntax_error("install requires an argument");
         if (_use_legacy_install()) {
             return install_app_legacy(transport_type, serial, argc, argv);
         }
         return install_app(transport_type, serial, argc, argv);
     }
     else if (!strcmp(argv[0], "install-multiple")) {
-        if (argc < 2) return usage("install-multiple requires an argument");
+        if (argc < 2) return syntax_error("install-multiple requires an argument");
         return install_multiple_app(transport_type, serial, argc, argv);
     }
     else if (!strcmp(argv[0], "uninstall")) {
-        if (argc < 2) return usage("uninstall requires an argument");
+        if (argc < 2) return syntax_error("uninstall requires an argument");
         if (_use_legacy_install()) {
             return uninstall_app_legacy(transport_type, serial, argc, argv);
         }
@@ -1847,12 +1829,12 @@ int adb_commandline(int argc, const char** argv) {
             // A local path or "android"/"data" arg was specified.
             src = argv[1];
         } else {
-            return usage("usage: adb sync [-l] [PARTITION]");
+            return syntax_error("adb sync [-l] [PARTITION]");
         }
 
         if (src != "" &&
             src != "system" && src != "data" && src != "vendor" && src != "oem") {
-            return usage("don't know how to sync %s partition", src.c_str());
+            return syntax_error("don't know how to sync %s partition", src.c_str());
         }
 
         std::string system_src_path = product_file("system");
@@ -1904,7 +1886,7 @@ int adb_commandline(int argc, const char** argv) {
         return restore(argc, argv);
     }
     else if (!strcmp(argv[0], "keygen")) {
-        if (argc != 2) return usage("keygen requires an argument");
+        if (argc != 2) return syntax_error("keygen requires an argument");
         // Always print key generation information for keygen command.
         adb_trace_enable(AUTH);
         return adb_auth_keygen(argv[1]);
@@ -1957,12 +1939,12 @@ int adb_commandline(int argc, const char** argv) {
                 std::string err;
                 return adb_query_command("host:reconnect-offline");
             } else {
-                return usage("usage: adb reconnect [device|offline]");
+                return syntax_error("adb reconnect [device|offline]");
             }
         }
     }
 
-    usage("unknown command %s", argv[0]);
+    syntax_error("unknown command %s", argv[0]);
     return 1;
 }
 
@@ -1989,19 +1971,18 @@ static int install_app(TransportType transport, const char* serial, int argc, co
     // The last argument must be the APK file
     const char* file = argv[argc - 1];
     if (!android::base::EndsWithIgnoreCase(file, ".apk")) {
-        fprintf(stderr, "Filename doesn't end .apk: %s\n", file);
-        return EXIT_FAILURE;
+        return syntax_error("filename doesn't end .apk: %s", file);
     }
 
     struct stat sb;
     if (stat(file, &sb) == -1) {
-        fprintf(stderr, "Failed to stat %s: %s\n", file, strerror(errno));
+        fprintf(stderr, "adb: failed to stat %s: %s\n", file, strerror(errno));
         return 1;
     }
 
     int localFd = adb_open(file, O_RDONLY);
     if (localFd < 0) {
-        fprintf(stderr, "Failed to open %s: %s\n", file, strerror(errno));
+        fprintf(stderr, "adb: failed to open %s: %s\n", file, strerror(errno));
         return 1;
     }
 
@@ -2019,7 +2000,7 @@ static int install_app(TransportType transport, const char* serial, int argc, co
 
     int remoteFd = adb_connect(cmd, &error);
     if (remoteFd < 0) {
-        fprintf(stderr, "Connect error for write: %s\n", error.c_str());
+        fprintf(stderr, "adb: connect error for write: %s\n", error.c_str());
         adb_close(localFd);
         return 1;
     }
@@ -2031,12 +2012,12 @@ static int install_app(TransportType transport, const char* serial, int argc, co
     adb_close(localFd);
     adb_close(remoteFd);
 
-    if (strncmp("Success", buf, 7)) {
-        fprintf(stderr, "Failed to install %s: %s", file, buf);
-        return 1;
+    if (!strncmp("Success", buf, 7)) {
+        fputs(buf, stdout);
+        return 0;
     }
-    fputs(buf, stderr);
-    return 0;
+    fprintf(stderr, "adb: failed to install %s: %s", file, buf);
+    return 1;
 }
 
 static int install_multiple_app(TransportType transport, const char* serial, int argc,
@@ -2058,10 +2039,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
         }
     }
 
-    if (first_apk == -1) {
-        fprintf(stderr, "No APK file on command line\n");
-        return 1;
-    }
+    if (first_apk == -1) return syntax_error("need APK file on command line");
 
     std::string install_cmd;
     if (_use_legacy_install()) {
@@ -2079,7 +2057,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
     std::string error;
     int fd = adb_connect(cmd, &error);
     if (fd < 0) {
-        fprintf(stderr, "Connect error for create: %s\n", error.c_str());
+        fprintf(stderr, "adb: connect error for create: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
     char buf[BUFSIZ];
@@ -2096,7 +2074,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
         }
     }
     if (session_id < 0) {
-        fprintf(stderr, "Failed to create session\n");
+        fprintf(stderr, "adb: failed to create session\n");
         fputs(buf, stderr);
         return EXIT_FAILURE;
     }
@@ -2107,7 +2085,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
         const char* file = argv[i];
         struct stat sb;
         if (stat(file, &sb) == -1) {
-            fprintf(stderr, "Failed to stat %s: %s\n", file, strerror(errno));
+            fprintf(stderr, "adb: failed to stat %s: %s\n", file, strerror(errno));
             success = 0;
             goto finalize_session;
         }
@@ -2119,7 +2097,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
 
         int localFd = adb_open(file, O_RDONLY);
         if (localFd < 0) {
-            fprintf(stderr, "Failed to open %s: %s\n", file, strerror(errno));
+            fprintf(stderr, "adb: failed to open %s: %s\n", file, strerror(errno));
             success = 0;
             goto finalize_session;
         }
@@ -2127,7 +2105,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
         std::string error;
         int remoteFd = adb_connect(cmd, &error);
         if (remoteFd < 0) {
-            fprintf(stderr, "Connect error for write: %s\n", error.c_str());
+            fprintf(stderr, "adb: connect error for write: %s\n", error.c_str());
             adb_close(localFd);
             success = 0;
             goto finalize_session;
@@ -2140,7 +2118,7 @@ static int install_multiple_app(TransportType transport, const char* serial, int
         adb_close(remoteFd);
 
         if (strncmp("Success", buf, 7)) {
-            fprintf(stderr, "Failed to write %s\n", file);
+            fprintf(stderr, "adb: failed to write %s\n", file);
             fputs(buf, stderr);
             success = 0;
             goto finalize_session;
@@ -2154,20 +2132,19 @@ finalize_session:
                                         install_cmd.c_str(), success ? "commit" : "abandon", session_id);
     fd = adb_connect(service, &error);
     if (fd < 0) {
-        fprintf(stderr, "Connect error for finalize: %s\n", error.c_str());
+        fprintf(stderr, "adb: connect error for finalize: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
     read_status_line(fd, buf, sizeof(buf));
     adb_close(fd);
 
     if (!strncmp("Success", buf, 7)) {
-        fputs(buf, stderr);
+        fputs(buf, stdout);
         return 0;
-    } else {
-        fprintf(stderr, "Failed to finalize session\n");
-        fputs(buf, stderr);
-        return EXIT_FAILURE;
     }
+    fprintf(stderr, "adb: failed to finalize session\n");
+    fputs(buf, stderr);
+    return EXIT_FAILURE;
 }
 
 static int pm_command(TransportType transport, const char* serial, int argc, const char** argv) {
@@ -2225,10 +2202,7 @@ static int install_app_legacy(TransportType transport, const char* serial, int a
         }
     }
 
-    if (last_apk == -1) {
-        fprintf(stderr, "No APK file on command line\n");
-        return EXIT_FAILURE;
-    }
+    if (last_apk == -1) return syntax_error("need APK file on command line");
 
     int result = -1;
     std::vector<const char*> apk_file = {argv[last_apk]};
diff --git a/commandline.h b/commandline.h
index 0cf655c..9ba69a3 100644
--- a/commandline.h
+++ b/commandline.h
@@ -87,7 +87,6 @@ class DefaultStandardStreamsCallback : public StandardStreamsCallbackInterface {
 extern DefaultStandardStreamsCallback DEFAULT_STANDARD_STREAMS_CALLBACK;
 
 int adb_commandline(int argc, const char** argv);
-int usage();
 
 // Connects to the device "shell" service with |command| and prints the
 // resulting output.