Many methods string shell intercepts
was $ {# * /}
$ {were ## * /}
$ {var% / *}
$ {were %% / *}
$ {were: start: len}
$ {were: starting}
$ {were: 0- start: len}
$ {var: 0 start}
The following example shows what a few:
1) obtaining a length of the string
grammar:
$ # {Was}
Sample code:
str="http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "string : [${str}]"
length=${#str}
echo "length : [${length}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] length : [61]
2) acquired using a # ## and trailing substring
2.1) # minimum word taken from the front
grammar:
${parameter#word}
Sample code:
str="http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "string : [${str}]"
#分割符为'/'
substr=${str#*/}
echo "substr : [${substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [/www.fengbohello.xin3e.com/blog/shell-truncating-string]
2.2) ## maximum word taken from the front
grammar:
${parameter##word}
Sample code:
str="http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "string : [${str}]"
#分割符为'/'
substr=${str##*/}
echo "substr : [${substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [shell-truncating-string]
3)%%% Get the head and the substrings
3.1)% minimum word taken from behind
grammar:
${parameter%word}
Sample code:
str="http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "string : [${str}]"
substr=${str%/*}
echo "substr : [${substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [http://www.fengbohello.xin3e.com/blog]
3.2) maximizing %% word taken from behind
grammar:
${parameter%%word}
Sample code:
str="http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "string : [${str}]"
substr=${str%%/*}
echo "substr : [${substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [http:]
4) $ {var:} mode acquiring substrings
4.1) Specifies the number of characters from the left of the first few characters of the start and substring
grammar:
$ {Var start: len}
Sample code:
= STR "http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "String: [STR $ {}]"
# 0 where the left side represents the first character, the sub-character 7 denotes of the total number.
STR $ {= substr: 0:. 7}
echo "substr: [$ {substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [http://]
4.2) from the left of the first few characters until the end
grammar:
$ {Var: 7}
Sample code:
= STR "http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "String: [STR $ {}]"
# 7 which represents the left of the first eight characters beginning
substr = $ {str :. 7}
echo "substr: [$ {substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [www.fengbohello.xin3e.com/blog/shell-truncating-string]
4.3) from the right side of the first few characters of the number and character of the beginning
grammar:
$ {Var: 0 start: len}
Sample code:
= STR "http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "String: [STR $ {}]"
# 0-23 where the right side represents the start date of 23 characters, 5 showing the number of characters
substr = $ {STR: 0-23: 5}
echo "substr: [$ {substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [shell]
4.4) starting from the right of the first few characters until the end
grammar:
Was $ {0} boot
Sample code:
= STR "http://www.fengbohello.xin3e.com/blog/shell-truncating-string"
echo "String: [STR $ {}]"
# 0-6 where the right side represents the sixth character starts counting
substr STR $ {=: 0-6}
echo "substr: [$ {substr}]"
Results of the:
string : [http://www.fengbohello.xin3e.com/blog/shell-truncating-string] substr : [string]