gbos - a tiny Unix-flavored OS for the Game Boy Color (kernel, shell, coreutils in C, RAM filesystem) https://git.sl0p.foo/gbos.git/atom/usr/nc.c?h=master 2026-09-22T14:02:55Z 2026-09-22T14:02:55Z user user@clank 2026-09-22T14:02:55Z urn:sha1:43e43b6dcec29e2b008d20135f5d02523b62fbcf The shell has had pipes for a while with nothing to pipe *through*, and an 18-row screen with no way to stop output scrolling off it. - grep [-vin] PAT [file]: substring match (no regex), stdin or a file, grep(1)'s exit convention. The other end of the pipe, at last. - more [file]: pages 17 lines at a time, --More-- bar in white-on-blue, any key pages, q quits. Counts *screen* rows, so wrapped lines pay their real cost. Keys come from pollin/pollcon, not stdin, so `cat big | more` still has a keyboard. - cp SRC DST: the fs has rm/mkdir but no way to duplicate a file. mv is this plus rm (there is no rename). Rejects SRC == DST, which would otherwise truncate the source via O_WRITE before reading a byte. - nc [-s] HOST PORT: raw TCP. Interactive (START sends the line with a CRLF, /q quits) or -s to pump stdin and print the reply with its own wall-clock idle timeout, because the kernel's blocking recv counts pumps, not seconds. Generalizes what chat/irc hardcode: `nc towel.blinkenlights.nl 23` works. sys_pollcon now pumps the link before draining the console ring. The ring is filled *by* net_pump, so a program that never touches the network polled a ring nothing would ever fill: host-injected keys (gbtype/gbdemo) hung `more` forever, and the Game Boy stopped answering pings for as long as it ran. KGetc already pumps for this reason. New tools take banks 35-38. Locals over statics in all four: a program's _DATA starts at $A000, where the shell leaves the command line.