使用sed

Question

我正在研究一个有很多功能的python模块。我想在某个特定位置的特定函数中插入几行。假设这是代码：

def abc():

    #few lines of code
    context =  {}
    return context

def xyz():

    #few lines of code
    context = {}
    return context  

现在我想在上下文之前添加“这是新行”，但仅在函数xyz中添加：

def abc():

    #few lines of code
    context =  {}
    return context

def xyz():

    #few lines of code
    This is new line
    context = {}
    return context 

如何使用sed执行此操作？此外，必须添加新行的功能可以在任何地方，无需在开头或结尾。

Answer 1

您可以使用awk完成此项工作：

输入文件：

cat file
def abc():

    #few lines of code
    context =  {}
    return context

def xyz():

    #few lines of code
    context = {}
    return context

def pqr():

    #few lines of code
    context =  {}
    return context

这是awk：

awk '/^def /{fnflag = index($0, " xyz()")}
    fnflag && /context = /{print "    This is new line"} 1' file
def abc():

    #few lines of code
    context =  {}
    return context

def xyz():

    #few lines of code
    This is new line
    context = {}
    return context

def pqr():

    #few lines of code
    context =  {}
    return context

Answer 2

试试这个：

sed '/^def xyz/,/^[[:space:]]*context/{s/^\([[:space:]]*\)context/\1This is new line\n&/;}' file

<强>说明：

• /^def xyz/,：从def xyz
开始的行
• /^[[:space:]]*context/：以空格（或制表符）开头，然后是context
• s/^\([[:space:]]*\)context/\1This is new line\n&/;：将空格/制表符和context替换为已捕获的空格，后跟新字符串后跟换行符（\n）

Answer 3

SED

sed -i '
    /def xyz\>/ {
        :A
        n
        /\<context\>/ {
            i\
    This is a new line
            bB
        }
        bA
    }
    :B
' file

有关:和b

的文档，请参阅the manual

我使用边界标记\<和\>来避免模式的模糊（即避免匹配def xyz123()）

或ed

ed file <<'END'
/def xyz\>
/\<context\>
i
    This is a new line
.
wq
END

Answer 4

懒惰的替代答案

sed  '/^def xyz/,/^def/ s/.*context =.*/   This is a new line\n&/'