On Linux:
echo -n $'boo\r\nboo\r\n' | awk $'BEGIN { RS="\\n" } {gsub("boo","foo"); print}' | cat -v
returns the expected
foo^M
foo^M
However, on mingw64 (git bash for windows) the same command returns:
foo
foo
without the carriage returns.
I tried setting the record separator explicitly since maybe the default was different between the two platforms, but awk on mingw64 is still chewing up the carriage returns. How can I made awk do the same thing on Linux on mingw64? Note the awk versions are slightly different (GNU Awk 4.0.2 on Linux and GNU Awk 4.2.1 on mingw64), but I wouldn't expect this to matter unless there is some kind of bug.
Note that something is happening specifically in awk since on mingw64 this:
echo -n $'boo\r\nboo\r\n' | cat -v
returns the expected:
boo^M
boo^M
After searching a while, I found this question, And from this answer :
it's something done by the C libraries and to stop it happening you should set the awk BINMODE variable to 3
I changed your code to:
echo -n $'boo\r\nboo\r\n' | awk -v BINMODE=3 $'BEGIN { RS="\\n" } {gsub("boo","foo"); print}' | cat -v
And tried it on Unix, Linux, MacOS, and Windows, all produce this output:
foo^M
foo^M
So -v BINMODE=3 is what you are looking for.
NOTE that only -v BINMODE=3 this switch & before code way working.
Usually we can pass variable to awk by -v switch, in BEGIN block, or set it after code before files,
but in this case I tried the three ways, only -v BINMODE=3 works.
Guess it's something to do with awk's compiling process.
Example (under cygwin on Windows):
$ echo -n $'boo\r\nboo\r\n' | awk -v BINMODE=3 '1' | cat -v
boo^M
boo^M
$ echo -n $'boo\r\nboo\r\n' | awk 'BEGIN{BINMODE=3}1' | cat -v
boo
boo
$ echo -n $'boo\r\nboo\r\n' | awk '1' BINMODE=3 | cat -v
boo
boo
Under other mentioned platforms, they all produce:
boo^M
boo^M