一个很简单的程序，是关于字符串操作的，就是几行代码，程序如下： module string;
reg[8*14:1] stringvar;
initial
begin
stringvar="Hello world";
$display("%s is stored as %h",stringvar,stringvar);
stringvar={stringvar,"!!!"};
$display("%s is stored as %h",stringvar,stringvar);
end
endmodule 运行的时候报错，错误如下： # ** Error: (vlog-7) Failed to open file "string/string/_primary.vhd" in w+b mode.
# No such file or directory. (errno = ENOENT)
# ** Error: (vlog-7) Failed to open library file "string/string/_primary.vhd" in write mode.
# No such file or directory. (errno = ENOENT)
# ** Error: E:/Modeltech_5.7e/examples/string/string.v(10): Verilog Compiler exiting 我用的是modelsim，好像说打开文件失败，麻烦各位帮忙看看，先谢谢了 | 
