Add util function to get the APK version

Use "dumpsys package com.genymobile.scrcpy" to get the APK version.

app/src/adb/adb.c

@@ -435,6 +435,7 @@ sc_adb_list_devices(struct sc_intr *intr, unsigned flags,
              "Please report an issue.");
         return false;
     }
+#undef BUFSIZE
 
     // It is parsed as a NUL-terminated string
     buf[r] = '\0';
@@ -758,3 +759,54 @@ sc_adb_get_installed_apk_path(struct sc_intr *intr, const char *serial,
 
     return sc_adb_parse_installed_apk_path(buf);
 }
+
+char *
+sc_adb_get_installed_apk_version(struct sc_intr *intr, const char *serial,
+                                 unsigned flags) {
+    assert(serial);
+    const char *const argv[] =
+        SC_ADB_COMMAND("-s", serial, "shell", "dumpsys", "package",
+                       SC_ANDROID_PACKAGE);
+
+    sc_pipe pout;
+    sc_pid pid = sc_adb_execute_p(argv, flags, &pout);
+    if (pid == SC_PROCESS_NONE) {
+        LOGD("Could not execute \"dumpsys package\"");
+        return NULL;
+    }
+
+    // "dumpsys package" output can be huge (e.g. 16k), but versionName is at
+    // the beginning, typically in the first 1024 bytes (64k should be enough
+    // for the whole output anyway)
+#define BUFSIZE 65536
+    char *buf = malloc(BUFSIZE);
+    if (!buf) {
+        return false;
+    }
+    ssize_t r = sc_pipe_read_all_intr(intr, pid, pout, buf, BUFSIZE - 1);
+    sc_pipe_close(pout);
+
+    bool ok = process_check_success_intr(intr, pid, "dumpsys package", flags);
+    if (!ok) {
+        free(buf);
+        return NULL;
+    }
+
+    if (r == -1) {
+        free(buf);
+        return NULL;
+    }
+
+    assert((size_t) r < BUFSIZE);
+#undef BUFSIZE
+    // if r == sizeof(buf), then the output is truncated, but we don't care,
+    // versionName is at the beginning in practice, and is unlikely to be
+    // truncated at 64k
+
+    // It is parsed as a NUL-terminated string
+    buf[r] = '\0';
+
+    char *version = sc_adb_parse_installed_apk_version(buf);
+    free(buf);
+    return version;
+}

app/src/adb/adb.h

@@ -123,4 +123,11 @@ char *
 sc_adb_get_installed_apk_path(struct sc_intr *intr, const char *serial,
                               unsigned flags);
 
+/**
+ * Return the version of the installed APK for com.genymobile.scrcpy (if any)
+ */
+char *
+sc_adb_get_installed_apk_version(struct sc_intr *intr, const char *serial,
+                                 unsigned flags);
+
 #endif

app/src/adb/adb_parser.c

@@ -253,3 +253,34 @@ sc_adb_parse_installed_apk_path(char *str) {
 
     return strdup(s);
 }
+
+char *
+sc_adb_parse_installed_apk_version(const char *str) {
+    // str is the (beginning of the) output of `dumpsys package`
+    // We want to extract the version string from a line starting with 4 spaces
+    // then `versionName=` then the version string.
+
+#define VERSION_NAME_PREFIX "\n    versionName="
+    char *s = strstr(str, VERSION_NAME_PREFIX);
+    if (!s) {
+        // Not found
+        return NULL;
+    }
+
+    s+= sizeof(VERSION_NAME_PREFIX) - 1;
+
+    size_t len = strspn(s, "0123456789.");
+    if (!len) {
+        LOGW("Unexpected version name with no value");
+        return NULL;
+    }
+
+    char *version = malloc(len + 1);
+    if (!version) {
+        return NULL;
+    }
+
+    memcpy(version, s, len);
+    version[len] = '\0';
+    return version;
+}

app/src/adb/adb_parser.h

@@ -38,4 +38,13 @@ sc_adb_parse_device_ip(char *str);
 char *
 sc_adb_parse_installed_apk_path(char *str);
 
+/**
+ * Parse the package version from the output of
+ * `adb shell dumpsys package <package>`
+ *
+ * The parameter must be a NUL-terminated string.
+ */
+char *
+sc_adb_parse_installed_apk_version(const char *str);
+
 #endif

app/tests/test_adb_parser.c

@@ -263,6 +263,32 @@ static void test_apk_path_invalid(void) {
     assert(!path);
 }
 
+static void test_apk_version(void) {
+    char str[] =
+        "Key Set Manager:\n"
+        "  [com.genymobile.scrcpy]\n"
+        "      Signing KeySets: 128\n"
+        "\n"
+        "Packages:\n"
+        "  Package [com.genymobile.scrcpy] (89abcdef):\n"
+        "    userId=12345\n"
+        "    pkg=Package{012345 com.genymobile.scrcpy}\n"
+        "    codePath=/data/app/~~abcdef==/com.genymobile.scrcpy-012345==\n"
+        "    resourcePath=/data/app/~~abcdef==/com.genymobile.scrcpy-013245==\n"
+        "    primaryCpuAbi=null\n"
+        "    secondaryCpuAbi=null\n"
+        "    versionCode=12400 minSdk=21 targetSdk=31\n"
+        "    versionName=1.24\n"
+        "    splits=[base]\n"
+        "    apkSigningVersion=2\n"
+        "    applicationInfo=ApplicationInfo{012345 com.genymobile.scrcpy}\n";
+
+    const char *expected = "1.24";
+    char *version = sc_adb_parse_installed_apk_version(str);
+    assert(!strcmp(version, expected));
+    free(version);
+}
+
 int main(int argc, char *argv[]) {
     (void) argc;
     (void) argv;
@@ -287,6 +313,7 @@ int main(int argc, char *argv[]) {
 
     test_apk_path();
     test_apk_path_invalid();
+    test_apk_version();
 
     return 0;
 }