shell 字串內含項目關聯性

# 方法1 —— 字元比較

#!/bin/bashstr1="hello"str2="he"str3="lo"if [ ${str1:0:2} = $str2 ]; then    echo "$str1 include $str2"fiif [ ${str1:2:4} = $str3 ]then    echo "$str1 include $str3"else    echo "$str1 not include $str3"fi

運行結果：

hello include he
hello not include lo

# 方法2 —— grep匹配

#!/bin/bashstr1="hello world"str2="he"str3="world "echo "$str1" | grep -q "$str2"if [ $? -eq 0 ]; then    echo "$str1 include $str2"fiecho "$str1" | grep -q "$str3"if [ $? -eq 0 ]; then    echo "$str1 include $str3"else    echo "$str1 not include $str3"fi

運行結果：

hello world include he
hello world not include world 

#方法3 —— 由方法2演變
echo "hello world" | grep -q "he" && echo "include" || echo "not include"           # result ： include

echo "hello world" | grep -q "world " && echo "include" || echo "not include"          # result ： not include

#方法4

#!/bin/bashstr1="hello world"str2="he"str3="world "[[ "${str1/$str2/}" != "$str2" ]] && echo "include" || echo "not include"[[ "${str1/$str2/}" != "$str2" ]]if [ $? -eq 0 ]; then    echo "$str1 include $str2"fi

運行結果：

include
hello world include he

#方法5 —— expr 命令

expr有模式比對功能，可以通過指定冒號選項計算字串中字元數，.* 即任何字元重複0次或多次

expr 計算字元數：

expr  "accounts.doc" : '.*'          # result ： 12

expr 截取字串

expr "accounts.doc" : '\(.*\).doc'         # result ： accounts

expr substr "hello world" 1 7              # result ： hello w

expr index "hello world" w                 # result ： 7

expr 截取數字

expr "string in 123 line" : '.*in\ \(.*\)'                # result ： 123 line

expr "string in 123 line" : '.*in\ \(.*\)line'           # result ： 123

expr "http://192.168.1.100/platform_example/branch/demo_platform is at revision 81" : '.*at\ revision\ \(.*\)'         # result： 81

substr 和 index 配合使用：

expr substr "hello world" 1 $(expr index "hello world" w)            # result ： hello w

#方法6 —— awk的index函數

awk 'BEGIN{info="this is hello world"; print index(info, "hello") ? "include" : "not include";}'            # result ： include

awk 'BEGIN{info="this is hello world"; print index(info, "helo") ? "include" : "not include";}'             # result ： not include

${var#...}                  
${var%...}
${var/.../...}

grep 精確匹配

1） echo "hello hellos hell" | grep hell               # result  ：  hello    hellos   hell

2） echo "hello hellos hell" | grep -w hell          # result  ：  hello    hellos   hell

3） echo "hello hellos hell" | grep "\<hell\>"      # result  ：  hello    hellos   hell

1） 模糊比對； 2） 單詞匹配； 3） 正則域匹配； 推薦方式3）

完整樣本：

test.txt

bird
birds
angrybird
angrybirds
angry bird
angry birds
angry birds war

grep.sh

#!/bin/bashcat test.txtechoecho "grep bird test.txt..."grep birds test.txtechoecho "grep -w bird test.txt..."grep -w birds test.txtechoecho "grep "\<birds\>" test.txt..."grep "\<birds\>" test.txt

運行結果：

bird
birds
angrybird
angrybirds
angry bird
angry birds
angry birds war

grep bird test.txt...
birds
angrybirds
angry birds
angry birds war

grep -w bird test.txt...
birds
angry birds
angry birds war

grep <birds> test.txt...
birds
angry birds
angry birds war

參考推薦：

shell 判斷字串是否存在內含項目關聯性

Shell expr的用法

awk 執行個體

linux awk 內建函數詳細介紹（推薦）

Linux 之 shell 比較子