ref: 75f5332c9dce891845e57b188efad28d7530d8ae
dir: /sys/src/cmd/upas/unesc/unesc.c/
/* * upas/unesc - interpret =?foo?bar?=char?= escapes */ #include <u.h> #include <libc.h> #include <bio.h> int hex(int c) { if('0' <= c && c <= '9') return c - '0'; if('a' <= c && c <= 'f') return c - 'a' + 10; if('A' <= c && c <= 'F') return c - 'A' + 10; return 0; } void main(void) { int c; Biobuf bin, bout; Binit(&bin, 0, OREAD); Binit(&bout, 1, OWRITE); while((c = Bgetc(&bin)) != Beof) if(c != '=') Bputc(&bout, c); else if((c = Bgetc(&bin)) != '?'){ Bputc(&bout, '='); Bputc(&bout, c); } else { while((c = Bgetc(&bin)) != Beof && c != '?') continue; /* consume foo */ while((c = Bgetc(&bin)) != Beof && c != '?') continue; /* consume bar */ while((c = Bgetc(&bin)) != Beof && c != '?'){ if(c == '='){ c = hex(Bgetc(&bin)) << 4; c |= hex(Bgetc(&bin)); } Bputc(&bout, c); } c = Bgetc(&bin); /* consume '=' */ if (c != '=') Bungetc(&bin); } Bterm(&bout); exits(0); }