Expose functions to get device serial and model

Expose functions to retrieve the device serial and model, as returned by
"adb get-serialno" and "adb shell getprop ro.product.model".

These functions require to execute a process with output redirection, so
also implement the necessary functions for both Unix and Windows.

app/src/command.c

@@ -34,10 +34,8 @@ static void show_adb_err_msg(enum process_result err) {
     }
 }
 
-process_t adb_execute(const char *serial, const char *const adb_cmd[], int len) {
+static void fill_cmd(const char *cmd[], const char *serial, const char *const adb_cmd[], int len) {
-    const char *cmd[len + 4];
     int i;
-    process_t process;
     cmd[0] = get_adb_command();
     if (serial) {
         cmd[1] = "-s";
@@ -49,6 +47,12 @@ process_t adb_execute(const char *serial, const char *const adb_cmd[], int len)
 
     memcpy(&cmd[i], adb_cmd, len * sizeof(const char *));
     cmd[len + i] = NULL;
+}
+
+process_t adb_execute(const char *serial, const char *const adb_cmd[], int len) {
+    const char *cmd[len + 4];
+    fill_cmd(cmd, serial, adb_cmd, len);
+    process_t process;
     enum process_result r = cmd_execute(cmd[0], cmd, &process);
     if (r != PROCESS_SUCCESS) {
         show_adb_err_msg(r);
@@ -57,6 +61,19 @@ process_t adb_execute(const char *serial, const char *const adb_cmd[], int len)
     return process;
 }
 
+process_t adb_execute_redirect(const char *serial, const char *const adb_cmd[], int len,
+                               pipe_t *pipe_stdin, pipe_t *pipe_stdout, pipe_t *pipe_stderr) {
+    const char *cmd[len + 4];
+    fill_cmd(cmd, serial, adb_cmd, len);
+    process_t process;
+    enum process_result r = cmd_execute_redirect(cmd[0], cmd, &process, pipe_stdin, pipe_stdout, pipe_stderr);
+    if (r != PROCESS_SUCCESS) {
+        show_adb_err_msg(r);
+        return PROCESS_NONE;
+    }
+    return process;
+}
+
 process_t adb_forward(const char *serial, uint16_t local_port, const char *device_socket_name) {
     char local[4 + 5 + 1]; // tcp:PORT
     char remote[108 + 14 + 1]; // localabstract:NAME
@@ -140,6 +157,40 @@ process_t adb_remove_path(const char *serial, const char *path) {
     return adb_execute(serial, adb_cmd, ARRAY_LEN(adb_cmd));
 }
 
+static int adb_execute_get_output(const char *serial, const char *const adb_cmd[], int adb_cmd_len,
+                           char *data, size_t data_len, const char *name) {
+    pipe_t pipe_stdout;
+    process_t proc = adb_execute_redirect(serial, adb_cmd, adb_cmd_len, NULL, &pipe_stdout, NULL);
+    if (!process_check_success(proc, name)) {
+        return -1;
+    }
+    int r = read_pipe(pipe_stdout, data, data_len);
+    close_pipe(pipe_stdout);
+    return r;
+}
+
+static int truncate_first_line(char *data, int len) {
+    data[len - 1] = '\0';
+    char *eol = strpbrk(data, "\r\n");
+    if (eol) {
+        *eol = '\0';
+        len = eol - data;
+    }
+    return len;
+}
+
+int adb_read_serialno(const char *serial, char *data, size_t len) {
+    const char *const adb_cmd[] = {"get-serialno"};
+    int r = adb_execute_get_output(serial, adb_cmd, ARRAY_LEN(adb_cmd), data, len, "get-serialno");
+    return r <= 0 ? r : truncate_first_line(data, r);
+}
+
+int adb_read_model(const char *serial, char *data, size_t len) {
+    const char *const adb_cmd[] = {"shell", "getprop", "ro.product.model"};
+    int r = adb_execute_get_output(serial, adb_cmd, ARRAY_LEN(adb_cmd), data, len, "getprop model");
+    return r <= 0 ? r : truncate_first_line(data, r);
+}
+
 SDL_bool process_check_success(process_t proc, const char *name) {
     if (proc == PROCESS_NONE) {
         LOGE("Could not execute \"%s\"", name);

app/src/command.h

@@ -47,6 +47,8 @@ SDL_bool cmd_terminate(process_t pid);
 SDL_bool cmd_simple_wait(process_t pid, exit_code_t *exit_code);
 
 process_t adb_execute(const char *serial, const char *const adb_cmd[], int len);
+process_t adb_execute_redirect(const char *serial, const char *const adb_cmd[], int len,
+                               pipe_t *pipe_stdin, pipe_t *pipe_stdout, pipe_t *pipe_stderr);
 process_t adb_forward(const char *serial, uint16_t local_port, const char *device_socket_name);
 process_t adb_forward_remove(const char *serial, uint16_t local_port);
 process_t adb_reverse(const char *serial, const char *device_socket_name, uint16_t local_port);
@@ -55,6 +57,10 @@ process_t adb_push(const char *serial, const char *local, const char *remote);
 process_t adb_install(const char *serial, const char *local);
 process_t adb_remove_path(const char *serial, const char *path);
 
+// return number of bytes read (-1 on error)
+int adb_read_serialno(const char *serial, char *data, size_t len);
+int adb_read_model(const char *serial, char *data, size_t len);
+
 // convenience function to wait for a successful process execution
 // automatically log process errors with the provided process name
 SDL_bool process_check_success(process_t process, const char *name);