Question

I need a (sed, awk) shell script or, even better, a Vim command to remove any blank lines following a line with a single opening curly bracket. For example,

void func()
{


    foo();
}

void bar()
{

    helloWorld();
}

should become

void func()
{
    foo();
}

void bar()
{
    helloWorld();
}

Any thoughts?

Answer 1

Try this:

$ awk 'NF{f=0}/^ *{/{ f=1 } f==1 && !NF{next}1' file
void func()
{
    foo();



}

A bit of explanation:

1. /^ *{/ means search for 0 or more blank spaces before the first {.
2. Then set a flag to true (f=1).
3. When the next line is read and f is true and !NF (means there is no fields, i.e., the line is blank), skip line using next.
4. When the next line which is not a blank line (i.e., NF{f=0} means toggle back the flag), the rest of the lines will not be affected until the next opening brace.