1.在bash中如何清除某个变量周围的空白符号（起到类似于Python中的strip()函数的作用）？

http://search.aol.com/aol/search?q=shell+strip+space

• http://stackoverflow.com/questions/13659318/how-to-remove-space-from-string
• http://stackoverflow.com/questions/369758/how-to-trim-whitespace-from-bash-variable
• Linux shell脚本的字符串截取等操作

方法一：tr命令

tr -d ' '
echo " test test test " | tr -d ' '

方法二：sed命令

# sed 's/ //g'
# echo " test test test " | sed 's/ *$//'
# echo " test test test " | sed 's/^ *//'
# echo " test test test " | sed -e 's/^ *//' -e 's/ *$//'

方法三：

字符串截取

# rtrim=${trimmed%% }
# ltrim=${trimmed## }

字符串替换

# echo ${s//[[:blank:]]/}

方法四：xargs命令

# echo " lol " | xargs

差不多就这些了，其它的也多多少少是一些变形……

2.获取文件的目录名/文件名

#!/bin/bash

# 1.获取脚本所在目录的名称
base_dir=$(dirname $0)/..
pwd
cd $base_dir
pwd

# 2.获取脚本的文件名
file_abs_name=$0
base_name=${file_abs_name##/*/}
base_name_no_ext=${base_name%.*}

• Linux shell脚本的字符串截取等操作

3.grep命令的一些tips

   -e PATTERN, --regexp=PATTERN
	  Use  PATTERN  as	the  pattern.	This  can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-).  (-e is specified by POSIX.)

   -f FILE, --file=FILE
	  Obtain patterns from FILE, one per line.	The empty file contains zero patterns, and therefore matches nothing.  (-f is specified by POSIX.)

   -i, --ignore-case
	  Ignore case distinctions in both the PATTERN and the input files.  (-i is specified by POSIX.)

   -v, --invert-match
	  Invert the sense of matching, to select non-matching lines.  (-v is specified by POSIX.)

   -c, --count
	  Suppress normal output; instead print a count of matching lines for each input file.  With the -v, --invert-match  option  (see  below),	count  non-matching lines.  (-c is specified by POSIX.)

   -l, --files-with-matches
	  Suppress	normal output; instead print the name of each input file from which output would normally have been printed.  The scanning will stop on the first match.  (-l is specified by POSIX.)

   -q, --quiet, --silent
	  Quiet; do not write anything to standard output.	Exit immediately with zero status if any match is found, even if an error was detected. Also see the -s or --no-messages option.  (-q is specified by POSIX.)

   -n, --line-number
	  Prefix each line of output with the 1-based line number within its input file.  (-n is specified by POSIX.)

Context Line Control
   -A NUM, --after-context=NUM
	  Print NUM lines of trailing context after matching lines.  Places a line containing a group separator (--)  between  contiguous  groups  of  matches. With the -o or --only-matching option, this has no effect and a warning is given.

   -B NUM, --before-context=NUM
	  Print  NUM  lines  of  leading  context before matching lines.  Places a line containing a group separator (--) between contiguous groups of matches. With the -o or --only-matching option, this has no effect and a warning is given.

   -C NUM, -NUM, --context=NUM
	  Print NUM lines of output context.  Places a line containing a  group  separator	(--)  between  contiguous  groups  of  matches.   With	the  -o  or --only-matching option, this has no effect and a warning is given.

 

# cat /proc/net/dev
Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
    lo:14551283   76129    0    0    0     0          0         0 14551283   76129    0    0    0     0       0          0
  eth0:18007778  145326    0    0    0     0          0         0   502374    3647    0    0    0     0       0          0
  sit0:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0

Method.2
# grep -A1 'lo:' /proc/net/dev | grep -v 'lo:' | awk -F':' '{print $1}'
  eth0

# grep -A1 'lo:' /proc/net/dev | grep -v 'lo:' | awk -F':' '{print $1}' | sed 's/[[:space:]]//g'
eth0

Method.3
In [5]: print os.popen("grep -A1 'lo:' /proc/net/dev | grep -v 'lo:' | awk -F':' '{print $1}' | sed 's/[[:space:]]//g'").read()
eth0
In [6]: print os.popen("grep -A1 'lo:' /proc/net/dev | grep -v 'lo:' | awk -F':' '{print $1}'").read().strip()
eth0

4.shell中的条件测试

• Shell条件测试
• File test operators http://tldp.org/LDP/abs/html/fto.html
• Introduction to if
• shell 条件测试 – AOL Search Results
• http://search.aol.com/aol/search?q=shell+file+if+test
• The Unix Shell’s Humble If
• shell 脚本之条件测试和流程结构
• 鸟哥的 Linux 私房菜 — 学习 Shell Scripts
• Shell脚本编程的常识
• Linux 技巧: Bash 测试和比较函数

5.使用shell脚本进行自动化测试

• http://stackoverflow.com/questions/971945/unit-testing-for-shell-scripts
• Using Bash shell scripts for function testing

6.查看Linux的内核版本命令

$ uname -a

$ lsb_release -a

$ cat /etc/issue

$ cat /proc/version

$ getconf LONG_BIT

$ file /bin/ls

$ arch

7.导出manual为txt文件

# man grep | col -b >grep_manual.txt