Question

shell 字符串的第一个字符怎么取

Answer 1

$ a='this is a string'
$ echo ${a:0:1}
t
用 ${var:0:1} 即可得到字符串变量的第一个字符

Answer 2

[chengmo@localhost ~]$ test='I love china'
[chengmo@localhost ~]$ echo ${test:5}
e china
[chengmo@localhost ~]$ echo ${test:5:10}
e china
${变量名:起始:长度}得到子字符串