| 变量名 | 作用 |
|---|---|
| [email protected] | 目标文件 |
| $^ | 所有依赖的文件 |
| $< | 第一个依赖文件 |
eg:
main : main.o dependent1.o dependent2.o
gcc -o main main.o dependent1.o dependent2.o
main.o : main.c dependent1.h dependent2.h
gcc -c main.c
使用 Makefile内置变量后：
main : main.o dependent1.o dependent2.o
gcc -o [email protected] $^
main.o : main.c dependent1.h dependent2.h
gcc -c $<
修改Terminal中的Show Prevous Tab和Show Next Tab的快捷键。
System Preferences —-> Keyboard —->Shortcuts —->App Shortcuts
修改后：
关键是Menu Title一定要和APP中的名字一致。
OS: Android 4.4 Kernel: 3.10.28
这里所谓的修改kernel version string并不是真的修改linux的版本号，因为那样会导致非常多的问题（比如一些驱动会不能用，等等）。所以这里修改的仅仅是/proc系统下的version，而从/proc/version中读取kernel version string是一个通常的做法，所以只需要修改这个就可以了。
kernel/fs/proc/version.c
static int version_proc_show(struct seq_file *m, void *v)
{
seq_printf(m, linux_proc_banner,
utsname()->sysname,
utsname()->release,
utsname()->version);
return 0;
}
seq_printf和printf的功能很类似，可以输出经格式化的字符串。这里的linux_proc_banner参数实际上是一个格式化字符串，它的定义在文件kernel/init/version.c中：
const char linux_proc_banner[] =
"%s version %s"
" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
" (" LINUX_COMPILER ") %s\n";
所以很明显你可以通过修改上面2个文件来定制你自己的version string.
接下来看看Android的setttings中是如何来读取kernel version的：
packages/apps/Settings/src/com/android/settings/DeviceInfoSettings.java
public static String getFormattedKernelVersion() {
try {
return formatKernelVersion(readLine(FILENAME_PROC_VERSION));
} catch (IOException e) {
Log.e(LOG_TAG,
"IO Exception when getting kernel version for Device Info screen",
e);
return "Unavailable";
}
}
我们看到Android并不是直接返回从/proc/version中读到的内容，而是经过了formatKernelVersion()方法的处理。否则会返回Unavailable。看一下formatKernelVersion()这个方法：
public static String formatKernelVersion(String rawKernelVersion) {
// Example (see tests for more):
// Linux version 3.0.31-g6fb96c9 ([email protected]) \
// (gcc version 4.6.x-xxx 20120106 (prerelease) (GCC) ) #1 SMP PREEMPT \
// Thu Jun 28 11:02:39 PDT 2012
final String PROC_VERSION_REGEX =
"Linux version (\\S+) " + /* group 1: "3.0.31-g6fb96c9" */
"\\((\\S+?)\\) " + /* group 2: "[email protected]" (kernel builder) */
"(?:\\(gcc.+? \\)) " + /* ignore: GCC version information */
"(#\\d+) " + /* group 3: "#1" */
"(?:.*?)?" + /* ignore: optional SMP, PREEMPT, and any CONFIG_FLAGS */
"((Sun|Mon|Tue|Wed|Thu|Fri|Sat).+)"; /* group 4: "Thu Jun 28 11:02:39 PDT 2012" */
Matcher m = Pattern.compile(PROC_VERSION_REGEX).matcher(rawKernelVersion);
if (!m.matches()) {
Log.e(LOG_TAG, "Regex did not match on /proc/version: " + rawKernelVersion);
return "Unavailable";
} else if (m.groupCount() < 4) {
Log.e(LOG_TAG, "Regex match on /proc/version only returned " + m.groupCount()
+ " groups");
return "Unavailable";
}
return m.group(1) + "\n" + // 3.0.31-g6fb96c9
m.group(2) + " " + m.group(3) + "\n" + // [email protected] #1
m.group(4); // Thu Jun 28 11:02:39 PDT 2012
}
呵呵，Android系统对version string做了正则匹配，所以我们不能随意修改version string,必须要保证这里的正则表达式和上一步中修改的version string能正确匹配，否则就会是unavailable.
Android OS: 4.4.4
Sometimes, you want to change the default MTP/PTP name of your android device. If you have android source, it’s very easy.
First open the source file:
frameworks/base/media/java/android/mtp/MtpDatabase.java, Line:799(in my source), or you can search the function getDeviceProperty
private int getDeviceProperty(int property, long[] outIntValue, char[] outStringValue) {
switch (property) {
case MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER:
case MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME:
// writable string properties kept in shared preferences
String value = mDeviceProperties.getString(Integer.toString(property), "");
int length = value.length();
if (length > 255) {
length = 255;
}
value.getChars(0, length, outStringValue, 0);
outStringValue[length] = 0;
return MtpConstants.RESPONSE_OK;
case MtpConstants.DEVICE_PROPERTY_IMAGE_SIZE:
// use screen size as max image size
Display display = ((WindowManager)mContext.getSystemService(
Context.WINDOW_SERVICE)).getDefaultDisplay();
int width = display.getMaximumSizeDimension();
int height = display.getMaximumSizeDimension();
String imageSize = Integer.toString(width) + "x" + Integer.toString(height);
imageSize.getChars(0, imageSize.length(), outStringValue, 0);
outStringValue[imageSize.length()] = 0;
return MtpConstants.RESPONSE_OK;
default:
return MtpConstants.RESPONSE_DEVICE_PROP_NOT_SUPPORTED;
}
}
Obviously, the outStringValue returned from DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME case section is the MTP name, so you can change the value whatever you want.
Then open the source file:
frameworks/av/media/mtp/MtpServer.cpp, Line:422(in my source), or you can search the function doGetDevInfo
MtpResponseCode MtpServer::doGetDeviceInfo() {
MtpStringBuffer string;
char prop_value[PROPERTY_VALUE_MAX];
MtpObjectFormatList* playbackFormats = mDatabase->getSupportedPlaybackFormats();
MtpObjectFormatList* captureFormats = mDatabase->getSupportedCaptureFormats();
MtpDevicePropertyList* deviceProperties = mDatabase->getSupportedDeviceProperties();
// fill in device info
mData.putUInt16(MTP_STANDARD_VERSION);
if (mPtp) {
mData.putUInt32(0);
} else {
// MTP Vendor Extension ID
mData.putUInt32(6);
}
mData.putUInt16(MTP_STANDARD_VERSION);
if (mPtp) {
// no extensions
string.set("");
} else {
// MTP extensions
string.set("microsoft.com: 1.0; android.com: 1.0;");
}
mData.putString(string); // MTP Extensions
mData.putUInt16(0); //Functional Mode
mData.putAUInt16(kSupportedOperationCodes,
sizeof(kSupportedOperationCodes) / sizeof(uint16_t)); // Operations Supported
mData.putAUInt16(kSupportedEventCodes,
sizeof(kSupportedEventCodes) / sizeof(uint16_t)); // Events Supported
mData.putAUInt16(deviceProperties); // Device Properties Supported
mData.putAUInt16(captureFormats); // Capture Formats
mData.putAUInt16(playbackFormats); // Playback Formats
property_get("ro.product.manufacturer", prop_value, "unknown manufacturer");
string.set(prop_value);
mData.putString(string); // Manufacturer
property_get("ro.product.model", prop_value, "MTP Device");
string.set(prop_value);
mData.putString(string); // Model
string.set("1.0");
mData.putString(string); // Device Version
property_get("ro.serialno", prop_value, "????????");
string.set(prop_value);
mData.putString(string); // Serial Number
delete playbackFormats;
delete captureFormats;
delete deviceProperties;
return MTP_RESPONSE_OK;
}
You need to change the Model String which read from the system ro.product.model property by default.
That’s all.
修改后的文件名格式：0001, 0002, …. 0100 …. 0999
Params: $1: 文件所在文件夹
$2: 目标文件的起始编号（宽度+1位）， 如：宽度为4位时需要附加一个宽度位（10001）
#!/bin/bash
cd $1
declare -i count
count=$2
ls * | while read file;
do
mv "$file" ${count:1}.jpg
count=$((count+1))
done
#下面的代码片段不能处理文件名中的空格，当然也可以使用IFS来解决这个问题
#for file in `ls`
#do
# mv $file ${count:1}.jpg
# count=$((count+1))
#done