ref: 8188b4f4f0e07b6669e6ae3c6c1099af917eaab4
dir: /sys/src/cmd/rc/simple.c/
/*
* Maybe `simple' is a misnomer.
*/
#include "rc.h"
#include "getflags.h"
#include "exec.h"
#include "io.h"
#include "fns.h"
/*
* Search through the following code to see if we're just going to exit.
*/
int
exitnext(void){
int i=ifnot;
thread *p=runq;
code *c;
loop:
c=&p->code[p->pc];
while(1){
if(c->f==Xpopredir || c->f==Xunlocal)
c++;
else if(c->f==Xsrcline)
c += 2;
else if(c->f==Xwastrue){
c++;
i=0;
}
else if(c->f==Xifnot){
if(i)
c += 2;
else
c = &p->code[c[1].i];
}
else if(c->f==Xreturn){
p = p->ret;
if(p==0)
return 1;
goto loop;
}else
break;
}
return c->f==Xexit;
}
void (*builtinfunc(char *name))(void)
{
extern builtin Builtin[];
builtin *bp;
for(bp = Builtin;bp->name;bp++)
if(strcmp(name, bp->name)==0)
return bp->fnc;
return 0;
}
void
Xsimple(void)
{
void (*f)(void);
word *a;
var *v;
int pid;
a = runq->argv->words;
if(a==0){
Xerror1("empty argument list");
return;
}
if(flag['x'])
pfmt(err, "%v\n", a); /* wrong, should do redirs */
v = gvlook(a->word);
if(v->fn)
execfunc(v);
else{
if(strcmp(a->word, "builtin")==0){
a = a->next;
if(a==0){
Xerror1("builtin: empty argument list");
return;
}
popword(); /* "builtin" */
}
f = builtinfunc(a->word);
if(f){
(*f)();
return;
}
if(exitnext()){
/* fork and wait is redundant */
pushword("exec");
execexec();
/* does not return */
}
else{
if((pid = execforkexec()) < 0){
Xerror2("try again", Errstr());
return;
}
poplist();
/* interrupts don't get us out */
while(Waitfor(pid) < 0)
;
}
}
}
static void
doredir(redir *rp)
{
if(rp){
doredir(rp->next);
switch(rp->type){
case ROPEN:
if(rp->from!=rp->to){
Dup(rp->from, rp->to);
Close(rp->from);
}
break;
case RDUP:
Dup(rp->from, rp->to);
break;
case RCLOSE:
Close(rp->from);
break;
}
}
}
word*
searchpath(char *w, char *v)
{
static struct word nullpath = { "", 0 };
word *path;
if(w[0] && w[0] != '/' && w[0] != '#' &&
(w[0] != '.' || (w[1] && w[1] != '/' && (w[1] != '.' || w[2] && w[2] != '/')))){
path = vlook(v)->val;
if(path)
return path;
}
return &nullpath;
}
char*
makepath(char *dir, char *file)
{
char *path;
int m, n = strlen(dir);
if(n==0) return estrdup(file);
while (n > 0 && dir[n-1]=='/') n--;
while (file[0]=='/') file++;
m = strlen(file);
path = emalloc(n + m + 2);
if(n>0) memmove(path, dir, n);
path[n++]='/';
memmove(path+n, file, m+1);
return path;
}
static char**
mkargv(word *a)
{
char **argv = (char **)emalloc((count(a)+2)*sizeof(char *));
char **argp = argv+1;
for(;a;a = a->next) *argp++=a->word;
*argp = 0;
return argv;
}
void
execexec(void)
{
char **argv;
word *path;
popword(); /* "exec" */
if(runq->argv->words==0){
Xerror1("exec: empty argument list");
return;
}
argv = mkargv(runq->argv->words);
Updenv();
doredir(runq->redir);
for(path = searchpath(argv[1], "path"); path; path = path->next){
argv[0] = makepath(path->word, argv[1]);
Exec(argv);
}
setstatus(Errstr());
pfln(err, srcfile(runq), runq->line);
pfmt(err, ": %s: %s\n", argv[1], getstatus());
Xexit();
}
void
execfunc(var *func)
{
popword(); /* name */
startfunc(func, Poplist(), runq->local, runq->redir);
}
void
execcd(void)
{
word *a = runq->argv->words;
word *cdpath;
char *dir;
setstatus("can't cd");
switch(count(a)){
default:
pfmt(err, "Usage: cd [directory]\n");
break;
case 2:
a = a->next;
for(cdpath = searchpath(a->word, "cdpath"); cdpath; cdpath = cdpath->next){
dir = makepath(cdpath->word, a->word);
if(Chdir(dir)>=0){
if(cdpath->word[0] != '\0' && strcmp(cdpath->word, ".") != 0)
pfmt(err, "%s\n", dir);
free(dir);
setstatus("");
break;
}
free(dir);
}
if(cdpath==0)
pfmt(err, "Can't cd %s: %s\n", a->word, Errstr());
break;
case 1:
a = vlook("home")->val;
if(a){
if(Chdir(a->word)>=0)
setstatus("");
else
pfmt(err, "Can't cd %s: %s\n", a->word, Errstr());
}
else
pfmt(err, "Can't cd -- $home empty\n");
break;
}
poplist();
}
void
execexit(void)
{
switch(count(runq->argv->words)){
default:
pfmt(err, "Usage: exit [status]\nExiting anyway\n");
case 2:
setstatus(runq->argv->words->next->word);
case 1: Xexit();
}
}
void
execshift(void)
{
int n;
word *a;
var *star;
switch(count(runq->argv->words)){
default:
pfmt(err, "Usage: shift [n]\n");
setstatus("shift usage");
poplist();
return;
case 2:
n = atoi(runq->argv->words->next->word);
break;
case 1:
n = 1;
break;
}
star = vlook("*");
for(;n>0 && star->val;--n){
a = star->val->next;
free(Freeword(star->val));
star->val = a;
star->changed = 1;
}
setstatus("");
poplist();
}
int
mapfd(int fd)
{
redir *rp;
for(rp = runq->redir;rp;rp = rp->next){
switch(rp->type){
case RCLOSE:
if(rp->from==fd)
fd=-1;
break;
case RDUP:
case ROPEN:
if(rp->to==fd)
fd = rp->from;
break;
}
}
return fd;
}
void
execcmds(io *input, char *file, var *local, redir *redir)
{
static union code rdcmds[5];
if(rdcmds[0].i==0){
rdcmds[0].i = 1;
rdcmds[1].s="*rdcmds*";
rdcmds[2].f = Xrdcmds;
rdcmds[3].f = Xreturn;
rdcmds[4].f = 0;
}
if(exitnext()) turfstack(local);
start(rdcmds, 2, local, redir);
runq->lex = newlexer(input, file);
}
void
execeval(void)
{
char *cmds;
int len;
io *f;
popword(); /* "eval" */
if(runq->argv->words==0){
Xerror1("Usage: eval cmd ...");
return;
}
Xqw(); /* make into single word */
cmds = Popword();
len = strlen(cmds);
cmds[len++] = '\n';
poplist();
f = openiostr();
pfln(f, srcfile(runq), runq->line);
pstr(f, " *eval*");
execcmds(openiocore(cmds, len), closeiostr(f), runq->local, runq->redir);
}
void
execdot(void)
{
int fd, bflag, iflag, qflag;
word *path, *argv;
char *file;
popword(); /* "." */
bflag = iflag = qflag = 0;
while(runq->argv->words && runq->argv->words->word[0]=='-'){
char *f = runq->argv->words->word+1;
if(*f == '-'){
popword();
break;
}
for(; *f; f++){
switch(*f){
case 'b':
bflag = 1;
continue;
case 'i':
iflag = 1;
continue;
case 'q':
qflag = 1;
continue;
}
goto Usage;
}
popword();
}
/* get input file */
if(runq->argv->words==0){
Usage:
Xerror1("Usage: . [-biq] file [arg ...]");
return;
}
argv = Poplist();
file = 0;
fd = -1;
for(path = searchpath(argv->word, "path"); path; path = path->next){
file = makepath(path->word, argv->word);
fd = Open(file, 0);
if(fd >= 0)
break;
if(strcmp(file, "/dev/stdin")==0){ /* for sun & ucb */
fd = Dup1(0);
if(fd>=0)
break;
}
free(file);
}
if(fd<0){
if(!qflag)
Xerror3(". can't open", argv->word, Errstr());
freewords(argv);
return;
}
execcmds(openiofd(fd), file, (var*)0, runq->redir);
pushredir(RCLOSE, fd, 0);
runq->lex->qflag = qflag;
runq->iflag = iflag;
if(iflag || !bflag && flag['b']==0){
runq->lex->peekc=EOF;
runq->lex->epilog="";
}
runq->local = newvar("*", runq->local);
runq->local->val = argv->next;
argv->next=0;
runq->local->changed = 1;
runq->local = newvar("0", runq->local);
runq->local->val = argv;
runq->local->changed = 1;
}
void
execflag(void)
{
char *letter, *val;
switch(count(runq->argv->words)){
case 2:
setstatus(flag[(unsigned char)runq->argv->words->next->word[0]]?"":"flag not set");
break;
case 3:
letter = runq->argv->words->next->word;
val = runq->argv->words->next->next->word;
if(strlen(letter)==1){
if(strcmp(val, "+")==0){
flag[(unsigned char)letter[0]] = flagset;
setstatus("");
break;
}
if(strcmp(val, "-")==0){
flag[(unsigned char)letter[0]] = 0;
setstatus("");
break;
}
}
default:
Xerror1("Usage: flag [letter] [+-]");
return;
}
poplist();
}
void
execwhatis(void){ /* mildly wrong -- should fork before writing */
word *a, *b, *path;
var *v;
char *file;
io *out;
int found, sep;
a = runq->argv->words->next;
if(a==0){
Xerror1("Usage: whatis name ...");
return;
}
setstatus("");
out = openiofd(mapfd(1));
for(;a;a = a->next){
v = vlook(a->word);
if(v->val){
pfmt(out, "%s=", a->word);
if(v->val->next==0)
pfmt(out, "%q\n", v->val->word);
else{
sep='(';
for(b = v->val;b && b->word;b = b->next){
pfmt(out, "%c%q", sep, b->word);
sep=' ';
}
pstr(out, ")\n");
}
found = 1;
}
else
found = 0;
v = gvlook(a->word);
if(v->fn)
pfmt(out, "fn %q %s\n", v->name, v->fn[v->pc-1].s);
else{
if(builtinfunc(a->word))
pfmt(out, "builtin %s\n", a->word);
else {
for(path = searchpath(a->word, "path"); path; path = path->next){
file = makepath(path->word, a->word);
if(Executable(file)){
pfmt(out, "%s\n", file);
free(file);
break;
}
free(file);
}
if(!path && !found){
pfmt(err, "%s: not found\n", a->word);
setstatus("not found");
}
}
}
flushio(out);
}
poplist();
free(closeiostr(out)); /* don't close fd */
}
void
execwait(void)
{
switch(count(runq->argv->words)){
default:
Xerror1("Usage: wait [pid]");
return;
case 2:
Waitfor(atoi(runq->argv->words->next->word));
break;
case 1:
Waitfor(-1);
break;
}
poplist();
}