在读取循环时使用sed替换单行

I'm needing help setting up a bash script for initializing some BC's in a file. Ideally, my program would iterate through each line and:
1) Read in BC type - (wall, outlet, inlet).
2) Change "type" field based on appropriate BC type.

我需要帮助设置一个bash脚本来初始化文件中的某些BC。理想情况下，我的程序将遍历每一行并且：1）读入BC类型 - （墙，出口，入口）。 2）根据适当的BC类型更改“类型”字段。

Unfortunately, my program seems to replace all type fields in Step 2 instead of only the type field associated with the correct BC.

不幸的是，我的程序似乎替换了步骤2中的所有类型字段，而不是仅替换与正确BC相关联的类型字段。

I think this has something to do with the sed command operating over the whole file instead of just the $line variable.

我认为这与操作整个文件的sed命令有关，而不仅仅是$ line变量。

while IFS= read -r line || [[ -n "$line" ]]; do                                         #go through each line of T2 file
        if [[ $line == *wall_* ]]                               #if wall_*
        then
                echo "attempted to assign wall_*"
                var=1 #wall                                     #Go down 2 lines
        elif [[ $line == *velocity-inlet* ]]
        then
                echo "attempted to assign outflow"
                var=2 #inlet
        elif [[ $line == *outflow* ]]
        then
                var=3 #outlet
        fi
        echo $var
        if [[ $line == *type* && $var == 1 ]]
        then
                sed -i 's/.*type.*/type                 zeroGradient/' 0/T3
                echo "Attempted wall zeroGradient"
        elif [[ $line == *type* && $var == 2 ]]
        then
                sed -i 's/.*type.*/type                 fixedValue\nvalue               uniform (3 0 0)/' 0/T3

        elif [[ $line == type* && $var == 3 ]]
        then
                sed -i 's/.*type.*/type                 zeroGradient/' 0/T3

        fi
        sed -i '/nFaces*/d' 0/T3                        #Deletes irrelevant stuff from boundary file copy
        sed -i '/startFace*/d' 0/T3
done <0/T3.

For example, it is supposed to change:

例如，它应该改变：

velocity-inlet_1  
{   
    type            patch;  
    nFaces          336;  
    startFace       75515;  
}  
outflow_2    
{  
    type            patch;  
    nFaces          136;  
    startFace       75851;  
}

To:

至：

velocity-inlet_1  
    {  
        type            fixedValue;  
        value           uniform (3 0 0);  
    }  
    outflow_2  
    {  
        type            zeroGradient;
    }

But instead changes it wrongly changes it to:

但改为错误地将其更改为：

velocity-inlet_1
    {
        type            fixedValue;
        value           uniform (3 0 0);
    }
    outflow_2
    {
        type            fixedValue;
        value           uniform (3 0 0);
    }

Help me stack overflow, you're my only hope.

帮我堆栈溢出，你是我唯一的希望。

1 个解决方案

#1

You have a few issues. sed will effect a whole line by default, and you're not telling it which line to modify in the first place. You're also modifying a file as you read it. I might go with something like this:

你有一些问题。默认情况下，sed将影响整行，并且您不会在第一时间告诉它要修改哪一行。您还在阅读时修改文件。我可能会这样：

var="none"
while IFS= read -r line; do
        if [[ "$line" =~ "wall" ]]; then
             var=wall
        elif [[ "$line" =~ "velocity-inlet" ]]; then
             var=inlet
        fi

        if [[ "$line" =~ "type" && "$var" == "wall" ]]; then
              echo "$line" | sed 's|\(type *\).*|\1zeroGradient|'
        elif [[ "$line" =~ "type" && "$var" == "inlet" ]]; then
              echo "$line" | sed 's|\(type *\).*|\1uniform (3 0 0)|'
        else
              echo "$line"
        fi
done

And then do

然后呢

 script.sh < 0/T3 > 0/T3.mod

You can of course modify this to read/write from particular files as well, and you can avoid sed (see here...)

你当然可以修改它来读取/写入特定文件，你可以避免使用sed（参见这里......）

#1