ref: ae61eb9381f6b0c70e1c52bf2c2b7f4cd0b5bb6f dir: /sys/src/libc/port/needsrcquote.c/
#include <u.h> #include <libc.h> int needsrcquote(int c) { if(c <= ' ') return 1; if(utfrune("`^#*[]=|\\?${}()'<>&;", c)) return 1; return 0; }