how to find out the existence of a file in system verilog

Question

I have a file abc/xyz.log in log directory. How can I find if the file exists or not in SystemVerilog class. If the file exists I want to delete the file.

Thanks.

Answer 1

You can use $fopen and it returns 0 if it doesn't exist. If it does exist, $fclose the file and then use $system("shell command") to delete it.

Answer 2

Using the Unix utility "test" (see "man test") through a $system call can do the job. It can also be done through direct C using the stat() function (much more cumbersome). This example can be leveraged to do what you want. In this case it checks for the existence of a directory and it not found, attempts to create it.

string report_dir;
report_dir  = {SIM_ROOT,"/",PROJ_NAME,"/",TECH_PROCESS,"/",LOGNAME,"/doc/functional"};
if ($system($sformatf("/usr/bin/test -d %s", report_dir)) != 0) begin
     $display("INFO: creating output directory %s", report_dir);
     if($system($sformatf("mkdir -p %s", report_dir)) != 0) begin
        $display("ERROR: mkdir -p %s returned an error", report_dir);
        $fatal(0);
     end
end
if($system($sformatf("/usr/bin/test -d %s -o -w %s", report_dir, report_dir)) != 0) begin
     $display("ERROR: output directory %s does not exist or is not writeable", report_dir);
     $fatal(0);
end