fileopen命令实现
fileopen命令是为了实现Mac系统下，在终端中用应用打开文件。
首先将目录/Users/huanghuan/Work/MyCMD 命令加入环境变量中，Mac下可配置在/etc/bashrc中。然后创建fileopen文件，其内容为：
1 #! /bin/sh
2 if [ $# != 2 ]
3 then
4 echo "输入参数错误!"
5 else
6 search_result=`find /Applications -maxdepth 1 -name *${1}*.app | wc -l`
7 app_list=`find /Applications -maxdepth 1 -name *${1}*.app`
8 if (($search_result<=0))
9 then
10 echo "未找到对应程序"
11 elif (($search_result==1))
12 then
13 echo "打开文件"
14 open ${app_list} ${2}
15 else
16 echo "符合条件的程序有:\n${app_list}"
17 echo "请重新输入正确的程序名"
18 fi
19 fi
20 exit
命令的运行效果如下：
PS:该命令将进一步完善，目前作为一个Shell练习而简单实现
todo命令实现
todo命令实际上就是实现了一个toDoList的小命令，配置如fileopen命令，其内容为：
1 #! /bin/sh
2
3 path="/Users/huanghuan/Work/MyCMD/toDoList"
4
5 while getopts a:r: option
6 do
7 case $option in
8 a)
9 echo ${OPTARG}" 创建时间:"`date +%Y年-%m月-%d日` >>$path
10 ;;
11 r)
12 if [ -f "$path" ]
13 then
14 gsed -i "${OPTARG}d" $path
15 fi
16 ;;
17 ?)
18 echo "Usage: toDo [-arp] [arg]"
19 echo "-a add todo item"
20 echo "-r remove todo item"
21 echo "-p print todo List"
22 exit
23 ;;
24 esac
25 done
26
27 echo "当前待办项目:"
28 if [ -f "$path" ]
29 then
30 cat -n $path
31 fi
32 exit
命令的运行效果如下：
该命令的扩展参见：todo扩展
Valid Phone Numbers
来源于Leetcode题目：Valid Phone Numbers
Given a text file file.txt that contains list of phone numbers (one per line), write a one liner bash script to print all valid phone numbers.
You may assume that a valid phone number must appear in one of the following two formats: (xxx) xxx-xxxx or xxx-xxx-xxxx. (x means a digit)
You may also assume each line in the text file must not contain leading or trailing white spaces.
For example, assume that file.txt has the following content:
987-123-4567
123 456 7890
(123) 456-7890
Your script should output the following valid phone numbers:
987-123-4567
(123) 456-7890
脚本代码：
grep -E '^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$' file.txt
使用-E可以少写很多转义字符，这道题还值得注意的是：what’s the difference between \d and [0-9] in grep
Transpose File
来源于Leetcode题目：Transpose File
Given a text file file.txt, transpose its content.
You may assume that each row has the same number of columns and each field is separated by the ‘ ‘ character.
For example, if file.txt has the following content:
name age
alice 21
ryan 30
Output the following:
name alice ryan
age 21 30
脚本代码：
awk -F ' ' 'BEGIN{line=0;column=1} {while(column<=NF){array[line,column]=$column; column++;} line++;column=1;} END{for(i=1;i<=NF;i++){for(j=0;j<line;j++){printf("%s",array[j,i]);if(j<line-1){printf(" ")}} printf("\n");}}' file.txt
Word Frequency
来源于Leetcode题目：Word Frequency
Write a bash script to calculate the frequency of each word in a text file words.txt.
For simplicity sake, you may assume:
words.txt contains only lowercase characters and space ‘ ‘ characters. Each word must consist of lowercase characters only. Words are separated by one or more whitespace characters. For example, assume that words.txt has the following content:
the day is sunny the the
the sunny is is
Your script should output the following, sorted by descending frequency:
the 4
is 3
sunny 2
day 1
Note: Don’t worry about handling ties, it is guaranteed that each word’s frequency count is unique.
脚本代码：
sed 's/ /\n/g' words.txt | sed '/^$/d' | sort | uniq -c | sort -nr | awk -F ' ' '{print $2" "$1}'