sed command & regular expression error All In One

read data & write data

regexp error

# /regexp/ 正则表达式后面少了一个 `/` ❌
sed "s/div/XYZ" ./multi-line-text.txt

# sed: 1: "s/div/XYZ": unterminated substitute in regular expression

solution

# /regexp/ 正则表达式后面少了一个 `/` ✅
sed "s/div/XYZ/" ./multi-line-text.txt >> multi-line-text.md

<div>line 01</div>
<div>line 02</div>
<div>line 03</div>
<div>line 04</div>
<div>line 05</div>
<div>line 06</div>
<div>line 07</div>
<div>line 08</div>
<div>line 09</div>
<div>line 10</div>

# sed `默认`不会直接修改源文件, 只是返回一个 STDOUT ✅
# sed "s/<div>/👻/" ./multi-line-text.txt

# sed 同时执行多个命令 `-e`, 使用英文的分号分隔 `;` ✅
# sed 的多个命令写在同一个双引号里面
# sed -e "s/<div>//; s/<\/div>//" ./multi-line-text.txt >> multi-line-text.md
sed -e "s/<div>/🎉/; s/<\/div>/👻/" ./multi-line-text.txt >> multi-line-text.md

insert data

insert new line data with a line break into first line


# clear first
rm -rf ./multi-line-text.md

# 双引号，多行文本 ❌
# sed -i '' "1i\
# Perl 🐪 camel\
# " ./multi-line-text.txt
# sed: 1: "1iPerl 🐪 camel": command i expects \ followed by text

solution 1: 1i


# 单引号，多行文本 ✅ 直接插入数据到原始文件
sed -i '' '1i\
Perl 🐪 camel\
' ./multi-line-text.txt

# sed -i '' '1i\
# Perl 🐪 camel\' ./multi-line-text.txt

# sed -i '' "1i\Perl 🐪 camel" ./multi-line-text.txt
# sed: 1: "1i\Perl 🐪 camel": extra characters after \ at the end of i command

# sed -i '' "1i Perl 🐪 camel" ./multi-line-text.txt
# sed: 1: "1i Perl 🐪 camel": command i expects \ followed by text

solution 2: 1s

# 1s 正则插入, 单引号 ✅
# sed -i '' '1s/^/Perl 🐪 camel\n/' ./multi-line-text.txt

# 1s 正则插入, 单引号 + 双引号 ✅
# sed -i "" '1s/^/Perl 🐪 camel\n/' ./multi-line-text.txt

# 1s 正则插入, 双引号 ✅
sed -i "" "1s/^/Perl 🐪 camel\n/" ./multi-line-text.txt

https://stackoverflow.com/a/74197534/5934465

https://stackoverflow.com/questions/6537490/insert-a-line-at-specific-line-number-with-sed-or-awk/74197534#74197534