ref: 0644aa11c120a581eec1d47c66208e08b946ec08
dir: /appl/cmd/p.b/
implement P; # Original by Steve Arons, based on Plan 9 p include "sys.m"; sys: Sys; FD: import Sys; include "draw.m"; include "string.m"; str: String; include "bufio.m"; bufio: Bufio; Iobuf: import bufio; include "sh.m"; stderr: ref FD; outb, cons: ref Iobuf; drawctxt: ref Draw->Context; nlines := 22; # 1/3rd 66-line nroff page (!) progname := "p"; P: module { init: fn(ctxt: ref Draw->Context, argv: list of string); }; usage() { sys->fprint(stderr, "Usage: p [-number] [file...]\n"); raise "fail:usage"; } init(ctxt: ref Draw->Context, argv: list of string) { sys = load Sys Sys->PATH; bufio = load Bufio Bufio->PATH; if(bufio == nil) nomod(Bufio->PATH); str = load String String->PATH; if(str == nil) nomod(String->PATH); sys->pctl(Sys->FORKFD, nil); drawctxt = ctxt; stderr = sys->fildes(2); if((stdout := sys->fildes(1)) != nil) outb = bufio->fopen(stdout, bufio->OWRITE); if(outb == nil){ sys->fprint(stderr, "p: can't open stdout: %r\n"); raise "fail:stdout"; } cons = bufio->open("/dev/cons", bufio->OREAD); if(cons == nil){ sys->fprint(stderr, "p: can't open /dev/cons: %r\n"); raise "fail:cons"; } if(argv != nil){ progname = hd argv; argv = tl argv; if(argv != nil){ s := hd argv; if(len s > 1 && s[0] == '-'){ (x, y) := str->toint(s[1:],10); if(y == "" && x > 0) nlines = x; else usage(); argv = tl argv; } } } if(argv == nil) argv = "-" :: nil; for(; argv != nil; argv = tl argv){ file := hd argv; fd: ref Sys->FD; if(file == "-"){ file = "stdin"; fd = sys->fildes(0); }else fd = sys->open(file, Sys->OREAD); if(fd == nil){ sys->fprint(stderr, "%s: can't open %s: %r\n", progname, file); continue; } page(fd); fd = nil; } } nomod(m: string) { sys->fprint(sys->fildes(2), "%s: can't load %s: %r\n", progname, m); raise "fail:load"; } page(fd: ref Sys->FD) { inb := bufio->fopen(fd, bufio->OREAD); nl := nlines; while((line := inb.gets('\n')) != nil){ outb.puts(line); if(--nl == 0){ outb.flush(); nl = nlines; pause(); } } outb.flush(); } pause() { for(;;){ cmdline := cons.gets('\n'); if(cmdline == nil || cmdline[0] == 'q') # catch ^d exit; else if(cmdline[0] == '!') { done := chan of int; spawn command(cmdline[1:], done); <-done; }else break; } } command(cmdline: string, done: chan of int) { sh := load Sh Sh->PATH; if(sh == nil) { sys->fprint(stderr, "%s: can't load %s: %r\n", progname, Sh->PATH); done <-= 0; return; } sys->pctl(Sys->FORKFD, nil); sys->dup(cons.fd.fd, 0); sh->system(drawctxt, cmdline); done <-= 1; }