V7/usr/src/cmd/osh.c
/*
*/
#include <setjmp.h>
#define INTR 2
#define QUIT 3
#define LINSIZ 1000
#define ARGSIZ 50
#define TRESIZ 100
#define QUOTE 0200
#define FAND 1
#define FCAT 2
#define FPIN 4
#define FPOU 8
#define FPAR 16
#define FINT 32
#define FPRS 64
#define TCOM 1
#define TPAR 2
#define TFIL 3
#define TLST 4
#define DTYP 0
#define DLEF 1
#define DRIT 2
#define DFLG 3
#define DSPR 4
#define DCOM 5
#define ENOMEM 12
#define ENOEXEC 8
int errval;
char *dolp;
char pidp[6];
char **dolv;
jmp_buf jmpbuf;
int dolc;
char *promp;
char *linep;
char *elinep;
char **argp;
char **eargp;
int *treep;
int *treeend;
char peekc;
char gflg;
char error;
char uid;
char setintr;
char *arginp;
int onelflg;
int stoperr;
#define NSIG 16
char *mesg[NSIG] {
0,
"Hangup",
0,
"Quit",
"Illegal instruction",
"Trace/BPT trap",
"IOT trap",
"EMT trap",
"Floating exception",
"Killed",
"Bus error",
"Memory fault",
"Bad system call",
0,
"Alarm clock",
"Terminated",
};
char line[LINSIZ];
char *args[ARGSIZ];
int trebuf[TRESIZ];
main(c, av)
int c;
char **av;
{
register f;
register char *acname, **v;
for(f=3; f<15; f++)
close(f);
dolc = getpid();
for(f=4; f>=0; f--) {
dolc = dolc/10;
pidp[f] = dolc%10 + '0';
}
v = av;
acname = "<none>";
promp = "% ";
if((uid = getuid()) == 0)
promp = "# ";
if(c>1 && v[1][0]=='-' && v[1][1]=='e') {
++stoperr;
v[1] = v[0];
++v;
--c;
}
if(c > 1) {
promp = 0;
if (*v[1]=='-') {
**v = '-';
if (v[1][1]=='c' && c>2)
arginp = v[2];
else if (v[1][1]=='t')
onelflg = 2;
} else {
close(0);
f = open(v[1], 0);
if(f < 0) {
prs(v[1]);
err(": cannot open",255);
}
}
}
if(**v == '-') {
signal(QUIT, 1);
f = signal(INTR, 1);
if ((arginp==0&&onelflg==0) || (f&01)==0)
setintr++;
}
dolv = v+1;
dolc = c-1;
loop:
if(promp != 0)
prs(promp);
peekc = getc();
main1();
goto loop;
}
main1()
{
register char *cp;
register *t;
argp = args;
eargp = args+ARGSIZ-5;
linep = line;
elinep = line+LINSIZ-5;
error = 0;
gflg = 0;
do {
cp = linep;
word();
} while(*cp != '\n');
treep = trebuf;
treeend = &trebuf[TRESIZ];
if(gflg == 0) {
if(error == 0) {
setjmp(jmpbuf);
if (error)
return;
t = syntax(args, argp);
}
if(error != 0)
err("syntax error",255); else
execute(t);
}
}
word()
{
register char c, c1;
*argp++ = linep;
loop:
switch(c = getc()) {
case ' ':
case '\t':
goto loop;
case '\'':
case '"':
c1 = c;
while((c=readc()) != c1) {
if(c == '\n') {
error++;
peekc = c;
return;
}
*linep++ = c|QUOTE;
}
goto pack;
case '&':
case ';':
case '<':
case '>':
case '(':
case ')':
case '|':
case '^':
case '\n':
*linep++ = c;
*linep++ = '\0';
return;
}
peekc = c;
pack:
for(;;) {
c = getc();
if(any(c, " '\"\t;&<>()|^\n")) {
peekc = c;
if(any(c, "\"'"))
goto loop;
*linep++ = '\0';
return;
}
*linep++ = c;
}
}
tree(n)
int n;
{
register *t;
t = treep;
treep =+ n;
if (treep>treeend) {
prs("Command line overflow\n");
error++;
longjmp(jmpbuf, 1);
}
return(t);
}
getc()
{
register char c;
if(peekc) {
c = peekc;
peekc = 0;
return(c);
}
if(argp > eargp) {
argp =- 10;
while((c=getc()) != '\n');
argp =+ 10;
err("Too many args",255);
gflg++;
return(c);
}
if(linep > elinep) {
linep =- 10;
while((c=getc()) != '\n');
linep =+ 10;
err("Too many characters",255);
gflg++;
return(c);
}
getd:
if(dolp) {
c = *dolp++;
if(c != '\0')
return(c);
dolp = 0;
}
c = readc();
if(c == '\\') {
c = readc();
if(c == '\n')
return(' ');
return(c|QUOTE);
}
if(c == '$') {
c = readc();
if(c>='0' && c<='9') {
if(c-'0' < dolc)
dolp = dolv[c-'0'];
goto getd;
}
if(c == '$') {
dolp = pidp;
goto getd;
}
}
return(c&0177);
}
readc()
{
int rdstat;
char cc;
register c;
if (arginp) {
if (arginp == 1)
exit(errval);
if ((c = *arginp++) == 0) {
arginp = 1;
c = '\n';
}
return(c);
}
if (onelflg==1)
exit(255);
if((rdstat = read(0, &cc, 1)) != 1)
if(rdstat==0) exit(errval); /* end of file*/
else exit(255); /* error */
if (cc=='\n' && onelflg)
onelflg--;
return(cc);
}
/*
* syntax
* empty
* syn1
*/
syntax(p1, p2)
char **p1, **p2;
{
while(p1 != p2) {
if(any(**p1, ";&\n"))
p1++; else
return(syn1(p1, p2));
}
return(0);
}
/*
* syn1
* syn2
* syn2 & syntax
* syn2 ; syntax
*/
syn1(p1, p2)
char **p1, **p2;
{
register char **p;
register *t, *t1;
int l;
l = 0;
for(p=p1; p!=p2; p++)
switch(**p) {
case '(':
l++;
continue;
case ')':
l--;
if(l < 0)
error++;
continue;
case '&':
case ';':
case '\n':
if(l == 0) {
l = **p;
t = tree(4);
t[DTYP] = TLST;
t[DLEF] = syn2(p1, p);
t[DFLG] = 0;
if(l == '&') {
t1 = t[DLEF];
t1[DFLG] =| FAND|FPRS|FINT;
}
t[DRIT] = syntax(p+1, p2);
return(t);
}
}
if(l == 0)
return(syn2(p1, p2));
error++;
return(0);
}
/*
* syn2
* syn3
* syn3 | syn2
*/
syn2(p1, p2)
char **p1, **p2;
{
register char **p;
register int l, *t;
l = 0;
for(p=p1; p!=p2; p++)
switch(**p) {
case '(':
l++;
continue;
case ')':
l--;
continue;
case '|':
case '^':
if(l == 0) {
t = tree(4);
t[DTYP] = TFIL;
t[DLEF] = syn3(p1, p);
t[DRIT] = syn2(p+1, p2);
t[DFLG] = 0;
return(t);
}
}
return(syn3(p1, p2));
}
/*
* syn3
* ( syn1 ) [ < in ] [ > out ]
* word word* [ < in ] [ > out ]
*/
syn3(p1, p2)
char **p1, **p2;
{
register char **p;
char **lp, **rp;
register *t;
int n, l, i, o, c, flg;
flg = 0;
if(**p2 == ')')
flg =| FPAR;
lp = 0;
rp = 0;
i = 0;
o = 0;
n = 0;
l = 0;
for(p=p1; p!=p2; p++)
switch(c = **p) {
case '(':
if(l == 0) {
if(lp != 0)
error++;
lp = p+1;
}
l++;
continue;
case ')':
l--;
if(l == 0)
rp = p;
continue;
case '>':
p++;
if(p!=p2 && **p=='>')
flg =| FCAT; else
p--;
case '<':
if(l == 0) {
p++;
if(p == p2) {
error++;
p--;
}
if(any(**p, "<>("))
error++;
if(c == '<') {
if(i != 0)
error++;
i = *p;
continue;
}
if(o != 0)
error++;
o = *p;
}
continue;
default:
if(l == 0)
p1[n++] = *p;
}
if(lp != 0) {
if(n != 0)
error++;
t = tree(5);
t[DTYP] = TPAR;
t[DSPR] = syn1(lp, rp);
goto out;
}
if(n == 0)
error++;
p1[n++] = 0;
t = tree(n+5);
t[DTYP] = TCOM;
for(l=0; l<n; l++)
t[l+DCOM] = p1[l];
out:
t[DFLG] = flg;
t[DLEF] = i;
t[DRIT] = o;
return(t);
}
scan(at, f)
int *at;
int (*f)();
{
register char *p, c;
register *t;
t = at+DCOM;
while(p = *t++)
while(c = *p)
*p++ = (*f)(c);
}
tglob(c)
int c;
{
if(any(c, "[?*"))
gflg = 1;
return(c);
}
trim(c)
int c;
{
return(c&0177);
}
execute(t, pf1, pf2)
int *t, *pf1, *pf2;
{
int i, f, pv[2];
register *t1;
register char *cp1, *cp2;
extern errno;
if(t != 0)
switch(t[DTYP]) {
case TCOM:
cp1 = t[DCOM];
if(equal(cp1, "chdir")) {
if(t[DCOM+1] != 0) {
if(chdir(t[DCOM+1]) < 0)
err("chdir: bad directory",255);
} else
err("chdir: arg count",255);
return;
}
if(equal(cp1, "shift")) {
if(dolc < 1) {
prs("shift: no args\n");
return;
}
dolv[1] = dolv[0];
dolv++;
dolc--;
return;
}
if(equal(cp1, "login")) {
if(promp != 0) {
execv("/bin/login", t+DCOM);
}
prs("login: cannot execute\n");
return;
}
if(equal(cp1, "newgrp")) {
if(promp != 0) {
execv("/bin/newgrp", t+DCOM);
}
prs("newgrp: cannot execute\n");
return;
}
if(equal(cp1, "wait")) {
pwait(-1, 0);
return;
}
if(equal(cp1, ":"))
return;
case TPAR:
f = t[DFLG];
i = 0;
if((f&FPAR) == 0)
i = fork();
if(i == -1) {
err("try again",255);
return;
}
if(i != 0) {
if((f&FPIN) != 0) {
close(pf1[0]);
close(pf1[1]);
}
if((f&FPRS) != 0) {
prn(i);
prs("\n");
}
if((f&FAND) != 0)
return;
if((f&FPOU) == 0)
pwait(i, t);
return;
}
if(t[DLEF] != 0) {
close(0);
i = open(t[DLEF], 0);
if(i < 0) {
prs(t[DLEF]);
err(": cannot open",255);
exit(255);
}
}
if(t[DRIT] != 0) {
if((f&FCAT) != 0) {
i = open(t[DRIT], 1);
if(i >= 0) {
lseek(i, 0L, 2);
goto f1;
}
}
i = creat(t[DRIT], 0666);
if(i < 0) {
prs(t[DRIT]);
err(": cannot create",255);
exit(255);
}
f1:
close(1);
dup(i);
close(i);
}
if((f&FPIN) != 0) {
close(0);
dup(pf1[0]);
close(pf1[0]);
close(pf1[1]);
}
if((f&FPOU) != 0) {
close(1);
dup(pf2[1]);
close(pf2[0]);
close(pf2[1]);
}
if((f&FINT)!=0 && t[DLEF]==0 && (f&FPIN)==0) {
close(0);
open("/dev/null", 0);
}
if((f&FINT) == 0 && setintr) {
signal(INTR, 0);
signal(QUIT, 0);
}
if(t[DTYP] == TPAR) {
if(t1 = t[DSPR])
t1[DFLG] =| f&FINT;
execute(t1);
exit(255);
}
gflg = 0;
scan(t, tglob);
if(gflg) {
t[DSPR] = "/etc/glob";
execv(t[DSPR], t+DSPR);
prs("glob: cannot execute\n");
exit(255);
}
scan(t, trim);
*linep = 0;
texec(t[DCOM], t);
cp1 = linep;
cp2 = "/usr/bin/";
while(*cp1 = *cp2++)
cp1++;
cp2 = t[DCOM];
while(*cp1++ = *cp2++);
texec(linep+4, t);
texec(linep, t);
prs(t[DCOM]);
err(": not found",255);
exit(255);
case TFIL:
f = t[DFLG];
pipe(pv);
t1 = t[DLEF];
t1[DFLG] =| FPOU | (f&(FPIN|FINT|FPRS));
execute(t1, pf1, pv);
t1 = t[DRIT];
t1[DFLG] =| FPIN | (f&(FPOU|FINT|FAND|FPRS));
execute(t1, pv, pf2);
return;
case TLST:
f = t[DFLG]&FINT;
if(t1 = t[DLEF])
t1[DFLG] =| f;
execute(t1);
if(t1 = t[DRIT])
t1[DFLG] =| f;
execute(t1);
return;
}
}
texec(f, at)
int *at;
{
extern errno;
register int *t;
t = at;
execv(f, t+DCOM);
if (errno==ENOEXEC) {
if (*linep)
t[DCOM] = linep;
t[DSPR] = "/usr/bin/osh";
execv(t[DSPR], t+DSPR);
prs("No shell!\n");
exit(255);
}
if (errno==ENOMEM) {
prs(t[DCOM]);
err(": too large",255);
exit(255);
}
}
err(s, exitno)
char *s;
int exitno;
{
prs(s);
prs("\n");
if(promp == 0) {
lseek(0, 0L, 2);
exit(exitno);
}
}
prs(as)
char *as;
{
register char *s;
s = as;
while(*s)
putc(*s++);
}
putc(c)
{
char cc;
cc = c;
write(2, &cc, 1);
}
prn(n)
int n;
{
register a;
if (a = n/10)
prn(a);
putc(n%10 + '0');
}
any(c, as)
int c;
char *as;
{
register char *s;
s = as;
while(*s)
if(*s++ == c)
return(1);
return(0);
}
equal(as1, as2)
char *as1, *as2;
{
register char *s1, *s2;
s1 = as1;
s2 = as2;
while(*s1++ == *s2)
if(*s2++ == '\0')
return(1);
return(0);
}
pwait(i, t)
int i, *t;
{
register p, e;
int s;
if(i != 0)
for(;;) {
p = wait(&s);
if(p == -1)
break;
e = s&0177;
if (e>=NSIG || mesg[e]) {
if(p != i) {
prn(p);
prs(": ");
}
if (e < NSIG)
prs(mesg[e]);
else {
prs("Signal ");
prn(e);
}
if(s&0200)
prs(" -- Core dumped");
}
if (e || s&&stoperr)
err("", (s>>8)|e );
errval =| (s>>8);
}
}