ref: 51bf59e016b43f16ec91943829af30d99a886cc1
dir: /appl/tiny/sh.b/
implement Sh;
include "sys.m";
sys: Sys;
FD: import Sys;
include "draw.m";
Context: import Draw;
include "filepat.m";
filepat: Filepat;
nofilepat := 0; # true if load Filepat has failed.
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "env.m";
env: Env;
stdin: ref FD;
stderr: ref FD;
waitfd: ref FD;
Quoted: con '\uFFF0';
stringQuoted: con "\uFFF0";
Sh: module
{
init: fn(ctxt: ref Context, argv: list of string);
};
Command: adt
{
args: list of string;
inf, outf: string;
append: int;
};
Async, Seq: con iota;
Pipeline: adt
{
cmds: list of ref Command;
term: int;
};
usage()
{
sys->fprint(stderr, "Usage: sh [-n] [-c cmd] [file]\n");
}
init(ctxt: ref Context, argv: list of string)
{
n: int;
arg: list of string;
buf := array[1024] of byte;
sys = load Sys Sys->PATH;
env = load Env Env->PATH;
stderr = sys->fildes(2);
waitfd = sys->open("#p/"+string sys->pctl(0, nil)+"/wait", sys->OREAD);
if(waitfd == nil){
sys->fprint(stderr, "sh: open wait: %r\n");
return;
}
eflag := nflag := lflag := 0;
cmd: string;
if(argv != nil)
argv = tl argv;
for(; argv != nil && len hd argv && (hd argv)[0]=='-'; argv = tl argv)
case hd argv {
"-e" =>
eflag = 1;
"-n" =>
nflag = 1;
"-l" =>
lflag = 1;
"-c" =>
argv = tl argv;
if(len argv != 1){
usage();
return;
}
cmd = hd argv;
* =>
usage();
return;
}
if (lflag)
startup(ctxt);
if(eflag == 0)
sys->pctl(sys->FORKENV, nil);
if(nflag == 0)
sys->pctl(sys->FORKNS, nil);
if(cmd != nil){
arg = tokenize(cmd+"\n");
if(arg != nil)
runit(ctxt, parseit(arg));
return;
}
if(argv != nil){
script(ctxt, hd argv);
return;
}
stdin = sys->fildes(0);
prompt := sysname() + "$ ";
for(;;){
sys->print("%s", prompt);
n = sys->read(stdin, buf, len buf);
if(n <= 0)
break;
arg = tokenize(string buf[0:n]);
if(arg != nil)
runit(ctxt, parseit(arg));
}
}
rev(arg: list of string): list of string
{
ret: list of string;
while(arg != nil){
ret = hd arg :: ret;
arg = tl arg;
}
return ret;
}
waitfor(pid: int)
{
if(pid <= 0)
return;
buf := array[sys->WAITLEN] of byte;
status := "";
for(;;){
n := sys->read(waitfd, buf, len buf);
if(n < 0){
sys->fprint(stderr, "sh: read wait: %r\n");
return;
}
status = string buf[0:n];
if(status[len status-1] != ':')
sys->fprint(stderr, "%s\n", status);
who := int status;
if(who != 0){
if(who == pid)
return;
}
}
}
mkprog(ctxt: ref Context, arg: list of string, infd, outfd: ref Sys->FD, waitpid: chan of int)
{
fds := list of {0, 1, 2};
if(infd != nil)
fds = infd.fd :: fds;
if(outfd != nil)
fds = outfd.fd :: fds;
pid := sys->pctl(sys->NEWFD, fds);
console := sys->fildes(2);
if(infd != nil){
sys->dup(infd.fd, 0);
infd = nil;
}
if(outfd != nil){
sys->dup(outfd.fd, 1);
outfd = nil;
}
waitpid <-= pid;
if(pid < 0 || arg == nil)
return;
{
exec(ctxt, arg, console);
}exception{
"fail:*" =>
#sys->fprint(console, "%s:%s\n", hd arg, e.name[5:]);
exit;
"write on closed pipe" =>
#sys->fprint(console, "%s: %s\n", hd arg, e.name);
exit;
}
}
exec(ctxt: ref Context, args: list of string, console: ref Sys->FD)
{
if (args == nil)
return;
cmd := hd args;
file := cmd;
if(len file<4 || file[len file-4:]!=".dis")
file += ".dis";
c := load Sh file;
if(c == nil) {
err := sys->sprint("%r");
if(err != "permission denied" && err != "access permission denied" && file[0]!='/' && file[0:2]!="./"){
c = load Sh "/dis/"+file;
if(c == nil)
err = sys->sprint("%r");
}
if(c == nil){
sys->fprint(console, "%s: %s\n", cmd, err);
return;
}
}
c->init(ctxt, args);
}
script(ctxt: ref Context, src: string)
{
bufio = load Bufio Bufio->PATH;
if(bufio == nil){
sys->fprint(stderr, "sh: load bufio: %r\n");
return;
}
f := bufio->open(src, Bufio->OREAD);
if(f == nil){
sys->fprint(stderr, "sh: open %s: %r\n", src);
return;
}
for(;;){
s := f.gets('\n');
if(s == nil)
break;
arg := tokenize(s);
if(arg != nil)
runit(ctxt, parseit(arg));
}
}
sysname(): string
{
fd := sys->open("#c/sysname", sys->OREAD);
if(fd == nil)
return "anon";
buf := array[128] of byte;
n := sys->read(fd, buf, len buf);
if(n < 0)
return "anon";
return string buf[0:n];
}
# Lexer.
tokenize(s: string): list of string
{
tok: list of string;
token := "";
instring := 0;
loop:
for(i:=0; i<len s; i++) {
if(instring) {
if(s[i] != '\'')
token = addchar(token, s[i]);
else if(i == len s-1 || s[i+1] != '\'') {
if(i == len s-1 || s[i+1] == ' ' || s[i+1] == '\t' || s[i+1] == '\n'){
tok = token :: tok;
token = "";
}
instring = 0;
} else {
token[len token] = '\'';
i++;
}
continue;
}
case s[i] {
' ' or '\t' or '\n' or '#' or
'\'' or '|' or '&' or ';' or
'>' or '<' or '\r' =>
if(token != "" && s[i]!='\''){
tok = token :: tok;
token = "";
}
case s[i] {
'#' =>
break loop;
'\'' =>
instring = 1;
'>' =>
ss := "";
ss[0] = s[i];
if(i<len s-1 && s[i+1]==s[i])
ss[1] = s[i++];
tok = ss :: tok;
'|' or '&' or ';' or '<' =>
ss := "";
ss[0] = s[i];
tok = ss :: tok;
}
* =>
token[len token] = s[i];
}
}
if(instring){
sys->fprint(stderr, "sh: unmatched quote\n");
return nil;
}
return rev(tok);
}
ismeta(char: int): int
{
case char {
'*' or '[' or '?' or
'#' or '\'' or '|' or
'&' or ';' or '>' or
'<' =>
return 1;
}
return 0;
}
addchar(token: string, char: int): string
{
if(ismeta(char) && (len token==0 || token[0]!=Quoted))
token = stringQuoted + token;
token[len token] = char;
return token;
}
# Parser.
getcommand(words: list of string): (ref Command, list of string)
{
args: list of string;
word: string;
si, so: string;
append := 0;
gather:
do {
word = hd words;
case word {
">" or ">>" =>
if(so != nil)
return (nil, nil);
words = tl words;
if(words == nil)
return (nil, nil);
so = hd words;
if(len so>0 && so[0]==Quoted)
so = so[1:];
if(word == ">>")
append = 1;
"<" =>
if(si != nil)
return (nil, nil);
words = tl words;
if(words == nil)
return (nil, nil);
si = hd words;
if(len si>0 && si[0]==Quoted)
si = si[1:];
"|" or ";" or "&" =>
break gather;
* =>
files := doexpand(word);
while(files != nil){
args = hd files :: args;
files = tl files;
}
}
words = tl words;
} while (words != nil);
return (ref Command(rev(args), si, so, append), words);
}
doexpand(file: string): list of string
{
if(file == nil)
return file :: nil;
if(len file>0 && file[0]==Quoted)
return file[1:] :: nil;
if (nofilepat)
return file :: nil;
for(i:=0; i<len file; i++)
if(file[i]=='*' || file[i]=='[' || file[i]=='?'){
if(filepat == nil) {
if ((filepat = load Filepat Filepat->PATH) == nil) {
sys->fprint(stderr, "sh: warning: cannot load %s: %r\n",
Filepat->PATH);
nofilepat = 1;
return file :: nil;
}
}
files := filepat->expand(file);
if(files != nil)
return files;
break;
}
return file :: nil;
}
revc(arg: list of ref Command): list of ref Command
{
ret: list of ref Command;
while(arg != nil) {
ret = hd arg :: ret;
arg = tl arg;
}
return ret;
}
getpipe(words: list of string): (ref Pipeline, list of string)
{
cmds: list of ref Command;
cur: ref Command;
word: string;
term := Seq;
gather:
while(words != nil) {
word = hd words;
if(word == "|")
return (nil, nil);
(cur, words) = getcommand(words);
if(cur == nil)
return (nil, nil);
cmds = cur :: cmds;
if(words == nil)
break gather;
word = hd words;
words = tl words;
case word {
";" =>
break gather;
"&" =>
term = Async;
break gather;
"|" =>
continue gather;
}
return (nil, nil);
}
if(word == "|")
return (nil, nil);
return (ref Pipeline(revc(cmds), term), words);
}
revp(arg: list of ref Pipeline): list of ref Pipeline
{
ret: list of ref Pipeline;
while(arg != nil) {
ret = hd arg :: ret;
arg = tl arg;
}
return ret;
}
parseit(words: list of string): list of ref Pipeline
{
ret: list of ref Pipeline;
cur: ref Pipeline;
while(words != nil) {
(cur, words) = getpipe(words);
if(cur == nil){
sys->fprint(stderr, "sh: syntax error\n");
return nil;
}
ret = cur :: ret;
}
return revp(ret);
}
# Runner.
runpipeline(ctx: ref Context, pipeline: ref Pipeline)
{
if(pipeline.term == Async)
sys->pctl(sys->NEWPGRP, nil);
pid := startpipeline(ctx, pipeline);
if(pid < 0)
return;
if(pipeline.term == Seq)
waitfor(pid);
}
startpipeline(ctx: ref Context, pipeline: ref Pipeline): int
{
pid := 0;
cmds := pipeline.cmds;
first := 1;
inpipe, outpipe: ref Sys->FD;
while(cmds != nil) {
last := tl cmds == nil;
cmd := hd cmds;
infd: ref Sys->FD;
if(!first)
infd = inpipe;
else if(cmd.inf != nil){
infd = sys->open(cmd.inf, Sys->OREAD);
if(infd == nil){
sys->fprint(stderr, "sh: can't open %s: %r\n", cmd.inf);
return -1;
}
}
outfd: ref Sys->FD;
if(!last){
fds := array[2] of ref Sys->FD;
if(sys->pipe(fds) < 0){
sys->fprint(stderr, "sh: can't make pipe: %r\n");
return -1;
}
outpipe = fds[0];
outfd = fds[1];
fds = nil;
}else if(cmd.outf != nil){
if(cmd.append){
outfd = sys->open(cmd.outf, Sys->OWRITE);
if(outfd != nil)
sys->seek(outfd, big 0, Sys->SEEKEND);
}
if(outfd == nil)
outfd = sys->create(cmd.outf, Sys->OWRITE, 8r666);
if(outfd == nil){
sys->fprint(stderr, "sh: can't open %s: %r\n", cmd.outf);
return -1;
}
}
rpid := chan of int;
spawn mkprog(ctx, cmd.args, infd, outfd, rpid);
pid = <-rpid;
infd = nil;
outfd = nil;
inpipe = outpipe;
outpipe = nil;
first = 0;
cmds = tl cmds;
}
return pid;
}
runit(ctx: ref Context, pipes: list of ref Pipeline)
{
while(pipes != nil) {
pipeline := hd pipes;
pipes = tl pipes;
if(pipeline.term == Seq)
runpipeline(ctx, pipeline);
else
spawn runpipeline(ctx, pipeline);
}
}
strchr(s: string, c: int): int
{
ln := len s;
for (i := 0; i < ln; i++)
if (s[i] == c)
return i;
return -1;
}
# PROFILE: con "/lib/profile";
PROFILE: con "/lib/infernoinit";
startup(ctxt: ref Context)
{
if (env == nil)
return;
# if (env->getenv("home") != nil)
# return;
home := gethome();
env->setenv("home", home);
escript(ctxt, PROFILE);
escript(ctxt, home + PROFILE);
}
escript(ctxt: ref Context, file: string)
{
fd := sys->open(file, Sys->OREAD);
if (fd != nil)
script(ctxt, file);
}
gethome(): string
{
fd := sys->open("/dev/user", sys->OREAD);
if(fd == nil)
return "/";
buf := array[128] of byte;
n := sys->read(fd, buf, len buf);
if(n < 0)
return "/";
return "/usr/" + string buf[0:n];
}