linux - tr, ^M deletion

去除 行尾的 ^M 字元

cmd> cat $(old_filename) | tr -d '\r' > $(new_filename)

linux - diff

不加入比對的目錄

$> diff -x 'exclude directory' directoryA directoryB

不加入比對的檔案

$> diff -X 'exclude file' directoryA directoryB

linux - diff and patch kernel

以內核(kernel)為例：


--test
|
kernel-new \ (directory)
|
kernel-old \ (directory)
|
patch-update (patched-file)

製作patch file，如果有兩個kernel目錄，一個較新一個較舊，利用diff指令比較差異後再重導向某一檔案

#diff -Nru kernel-old kernel-new > patch-update

--test
|
kernel-new \
|
patch-update

使用patch file，拿到patch file後update到目錄裡

#> cd kernel-old

update

#> patch -p1 < patch-update

或

#> cat patch-update | patch -p1

( --dry-run is good param. if not sure -pX value is )

patch file是壓縮檔或是打包形式

#> bzcat patch-update.bz2 | patch -p1

或

#> zcat patch-update.gz | patch -p1

恢復patch前

#> patch -p1 -R < patch-update

linux - u-boot ( 1st boot msg.)

u-boot 初次開機，出現訊息

*** Warning - bad CRC, using default environment

未初始化環境變數，設定環境變數後即可 ( ex: set macaddr ff:ff:ff:ff:ff:ff )

*** Warning - bad CRC, using default environment

linux - grep, find

找出所有 檔名為readme 且 內含字串 "help"

#> grep help $(find . -name readme)