1 第一个shell脚本
2 #!/bin/bash
3 echo "Hello World"
4
5 使用read从标准输入获取输入并赋值给变量，然后输出
6 #!/bin/bash
7
8 # Author : zjw
9 # Copyright @ www.litsoft.com
10 # Script follow here:
11
12 echo "what is your name?"
13 read PERSON
14 echo "Hello, $PERSON"
15
16 使用变量，并使用了for循环
17 #!/bin/bash
18
19 for skill in Ada Coffe Action Java
20 do
21 echo "I am good at ${skill} Script."
22 done
23
24 echo "Over"
25
26 重定义变量
27 #!/bin/bash
28
29 myUrl="Http://www.litsoft.com"
30 echo ${myUrl}
31
32 myUrl="Http://www.myblog.com"
33 echo ${myUrl}
34
35 echo "Over"
36
37
38 只读变量
39 #!/bin/bash
40
41 myUrl="Http://www.litsoft.com"
42 echo ${myUrl}
43
44 readonly myUrl
45
46 myUrl="Http://www.myblog.com"
47 echo ${myUrl}
48
49 echo "Over"
50
51
52 删除变量
53 #!/bin/bash
54
55 myUrl="Http://www.litsoft.com"
56 echo ${myUrl}
57
58 unset myUrl
59
60 #myUrl="Http://www.myblog.com"
61 echo ${myUrl}
62
63 echo "Over"
64
65
66 特殊变量，命令行参数
67 #!/bin/bash
68
69 echo "File Name : $0"
70 echo "First Parameter : $1"
71 echo "Second Parameter : $2"
72 echo "Quoted Values : $@"
73 echo "Quoted Values : $*"
74 echo "Total Number of Parameters : $#"
75
76
77 变量替换
78 #!/bin/bash
79
80 a=10
81 echo -e "Value of a is $a \n"
82 echo "Over"
83
84
85 命令替换
86 #!/bin/bash
87 DATE=date
88 echo "Date is $DATE"
89
90 USERS=who | wc -l
91 echo "Logged in user are $USERS"
92
93 UP=date; uptime
94 echo "Uptime is &UP"
95
96
97 变量替换
98 #!/bin/bash
99
100 echo ${var:-"Variable is not set"}
101 echo "1 - Value of var is ${var}"
102
103 echo ${var:="Variable is not set"}
104 echo "2 - Value of var is ${var}"
105
106 unset var
107 echo ${var:+"This is default value"}
108 echo "3 - Value of var is $var"
109
110 var="Prefix"
111 echo ${var:+"This is default value"}
112 echo "4 - Value of var is $var"
113
114 echo ${var:?"Print this message"}
115 echo "5 - Value of var is ${var}"
116
117
118 ===========================shell运算符============================================
119 算术运算符
120 #!/bin/bash
121
122 val= expr 2 + 2
123
124 echo "Total value : $val"
125
126 #!/bin/bash
127
128 a=10
129 b=20
130 val= expr $a + $b
131 echo "a + b : $val"
132
133 val= expr $a - $b
134 echo "a - b : $val"
135
136 val= expr $a \* $b
137 echo "a * b : $val"
138
139 val= expr $b / $a
140 echo "b / a : $val"
141
142 val= expr $b % $a
143 echo "b % a : $val"
144
145 if [ $a == $b ]
146 then
147 echo "a is equal to b"
148 fi
149
150 if [ $a != $b ]
151 then
152 echo "a is not equal to b"
153 fi
154
155
156 关系运算符
157 #!/bin/sh
158
159 a=10
160 b=20
161 if [ $a -eq $b ]
162 then
163 echo "$a -eq $b : a is equal to b"
164 else
165 echo "$a -eq $b : a is not equal to b"
166 fi
167
168 if [ $a -ne $b ]
169 then
170 echo "$a -ne $b : a is not equal to b"
171 else
172 echo "$a -ne $b : a is equal to b"
173 fi
174
175 if [ $a -gt $b ]
176 then
177 echo "$a -gt $b : a is greater than b"
178 else
179 echo "$a -gt $b : a is not greater than b"
180 fi
181
182 if [ $a -lt $b ]
183 then
184 echo "$a -lt $b : a is less than b"
185 else
186 echo "$a -lt $b : a is not less than b"
187 fi
188
189 if [ $a -ge $b ]
190 then
191 echo "$a -ge $b : a is greater or equal to b"
192 else
193 echo "$a -ge $b : a is not greater or equal to b"
194 fi
195
196 if [ $a -le $b ]
197 then
198 echo "$a -le $b : a is less or equal to b"
199 else
200 echo "$a -le $b : a is no less or equal to b"
201 fi
202
203
204 布尔运算符
205 #!/bin/bash
206
207 a=10
208 b=20
209
210 if [ $a != $b ]
211 then
212 echo "$a != $b : a is not equal to b"
213 else
214 echo "$a != $b : a is equal to b"
215 fi
216
217 if [ $a -lt 100 -a $b -gt 15 ]
218 then
219 echo "$a -lt 100 -a $b -gt 15 : return true"
220 else
221 echo "$a -lt 100 -a $b -gt 15 : return false"
222 fi
223
224 if [ $a -lt 100 -o $b -gt 100 ]
225 then
226 echo "$a -lt 100 -o $b -gt 100 : return true"
227 else
228 echo "$a -lt 100 -o $b -gt 100 : return false"
229 fi
230
231 if [ $a -lt 5 -o $b -gt 100 ]
232 then
233 echo "$a -lt 100 -o $b -gt 100 : return true"
234 else
235 echo "$a -lt 100 -o $b -gt 100 : return false"
236 fi
237
238
239 字符串运算符
240 #!/bin/bash
241
242 a="abc"
243 b="efg"
244
245 if [ $a = $b ]
246 then
247 echo "$a = $b : a is equal to b"
248 else
249 echo "$a = $b : a is not equal to b"
250 fi
251
252 if [ $a != $b ]
253 then
254 echo "$a != $b : a is not equal to b"
255 else
256 echo "$a != $b : a is equal to b"
257 fi
258
259 if [ -z $a ]
260 then
261 echo "-z $a : string length is zero"
262 else
263 echo "-z $a : string length is not zero"
264 fi
265
266 if [ -n $a ]
267 then
268 echo "-n $a : string length is not zero"
269 else
270 echo "-n $a : string length is zero"
271 fi
272
273 if [ $a ]
274 then
275 echo "$a : string is not empty"
276 else
277 echo "$a : string is empty"
278 fi
279
280
281 文件测试运算符
282 #!/bin/bash
283
284 file="/mnt/hgfs/work/mycode/shell/1.sh"
285
286 if [ -r $file ]
287 then
288 echo "File has read access"
289 else
290 echo "File does not have read access"
291 fi
292
293 if [ -w $file ]
294 then
295 echo "File has write permission"
296 else
297 echo "File does not have write permission"
298 fi
299
300 if [ -x $file ]
301 then
302 echo "File has execute permission"
303 else
304 echo "File does not has execute permission"
305 fi
306
307 if [ -f $file ]
308 then
309 echo "File is an ordinary file"
310 else
311 echo "This is a spcial file"
312 fi
313
314 if [ -d $file ]
315 then
316 echo "File is a directory file"
317 else
318 echo "This is not a directory file"
319 fi
320
321 if [ -s $file ]
322 then
323 echo "File size is zero"
324 else
325 echo "File size is not zero"
326 fi
327
328 if [ -e $file ]
329 then
330 echo "File exists"
331 else
332 echo "File does not exist"
333 fi
