Plan 9 from Bell Labs’s /usr/web/sources/nix/nix/sys/src/libString/s_putc.c
#include <u.h> #include <libc.h> #include "String.h" void s_putc(String *s, int c) { if(s->ref > 1) sysfatal("can't s_putc a shared string"); if (s->ptr >= s->end) s_grow(s, 2); *(s->ptr)++ = c; }