ANMIAN

원문 : http://www.hypexr.org/linux_scp_help.php

What is Secure Copy?

scp allows files to be copied to, from, or between different hosts. It uses ssh for data transfer and provides the same authentication and same level of security as ssh.

Examples

Copy the file "foobar.txt" from a remote host to the local host

$ scp your_username@remotehost.edu:foobar.txt /some/local/directory

Copy the file "foobar.txt" from the local host to a remote host

$ scp foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy the directory "foo" from the local host to a remote host's directory "bar"

$ scp -r foo your_username@remotehost.edu:/some/remote/directory/bar

Copy the file "foobar.txt" from remote host "rh1.edu" to remote host "rh2.edu"

$ scp your_username@rh1.edu:/some/remote/directory/foobar.txt \ your_username@rh2.edu:/some/remote/directory/

Copying the files "foo.txt" and "bar.txt" from the local host to your home directory on the remote host

$ scp foo.txt bar.txt your_username@remotehost.edu:~

Copy the file "foobar.txt" from the local host to a remote host using port 2264

$ scp -P 2264 foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy multiple files from the remote host to your current directory on the local host

$ scp your_username@remotehost.edu:/some/remote/directory/\{a,b,c\} .

$ scp your_username@remotehost.edu:~/\{foo.txt,bar.txt\} .

scp Performance

By default scp uses the Triple-DES cipher to encrypt the data being sent. Using the Blowfish cipher has been shown to increase speed. This can be done by using option -c blowfish in the command line.

$ scp -c blowfish some_file your_username@remotehost.edu:~

It is often suggested that the -C option for compression should also be used to increase speed. The effect of compression, however, will only significantly increase speed if your connection is very slow. Otherwise it may just be adding extra burden to the CPU. An example of using blowfish and compression:

$ scp -c blowfish -C local_file your_username@remotehost.edu:~

tar 분할압축 :

tar cvfz - /PATH/* | split -b 1m - tets.tar.gz

1m 단위로 분할압축

tar 압축 풀기 : 

cat test.tar.gz* | tar xvfz -

gzip 분할압축

tar cvf - /PATH/* | gzip - | split -b 1m - test.tar.gz

gzip 압축 풀기

cat test.tar.gz* | gzip -d - | tar xvf -

여기서 - 는 stdio 를 의미한다.

frameworks/compile/slang/slang_rs_export_foreach.cpp:247:23: error: variable ‘ParamName’ set but not used [-Werror=unused-but-set-variable]

cc1plus: all warnings being treated as errors

SOLUTION

Fix/Workaround:

frameworks/compile/slang/Android.mk

-local_cflags_for_slang := -Wno-sign-promo -Wall -Wno-unused-parameter -Werror 

+local_cflags_for_slang := -Wno-sign-promo -Wall -Wno-unused-parameter

# cat /proc/sys/kernel/printk

6 4 1 7

=> 맨 처음 숫자가 Log Level을 의미함

#define KERN_EMERG "<0>" /* system is unusable */

#define KERN_ALERT "<1>" /* action must be taken immediately */

#define KERN_CRIT "<2>" /* critical conditions */

#define KERN_ERR "<3>" /* error conditions */

#define KERN_WARNING "<4>" /* warning conditions */

#define KERN_NOTICE "<5>" /* normal but significant condition */

#define KERN_INFO "<6>" /* informational */

#define KERN_DEBUG "<7>" /* debug-level messages */

echo 7 4 1 7 > /proc/sys/kernel/printk

로 설정하면 모든 printk 는 출력되며

echo 0 4 1 7 > /proc/sys/kernel/printk

로 설정하면 모든 printk 는 출력되지 않는다

출처 : KELP (Korea Embedded Linux Project)