+/*
+
+ * Copyright (c) 1984, 1985, 1986 AT&T
+ * All Rights Reserved
+
+ * THIS IS UNPUBLISHED PROPRIETARY SOURCE
+ * CODE OF AT&T.
+ * The copyright notice above does not
+ * evidence any actual or intended
+ * publication of such source code.
+
+ */
+/* @(#)main.c 1.1 */
+/*
+ * UNIX shell
+ *
+ * S. R. Bourne
+ * Rewritten by David Korn
+ * AT&T Bell Laboratories
+ *
+ */
+
+#ifdef BSD
+# ifdef BSD_4_2
+# include <sys/param.h>
+# else
+# include <sys/types.h>
+# endif /* BSD_4_2 */
+#include <sgtty.h>
+#else
+#include <sys/types.h>
+#endif /* BSD */
+#include <sys/stat.h>
+#include "defs.h"
+#include "sym.h"
+#include "flags.h"
+#include "io.h"
+#include "history.h"
+#include "mode.h"
+#include "name.h"
+#include "stak.h"
+#include "timeout.h"
+#include "brkincr.h"
+#include "builtins.h"
+#ifdef pdp11
+#include <execargs.h>
+#endif /* pdp11 */
+
+#define FC_CHAR '!'
+
+
+/* These routines are defined by this module */
+int main();
+void chkpr();
+char *getpwd();
+
+/* These routines are referenced by this module */
+extern void addblok();
+extern void assign();
+extern FILE *chkopen();
+extern TREPTR cmd();
+extern void done();
+extern void fassign();
+extern char *getpwd();
+extern void gscan_some();
+extern int hist_open();
+extern void hist_close();
+extern void hist_eof();
+extern void hist_flush();
+extern void initf();
+extern char *itos();
+extern char *mactry();
+extern char *movstr();
+extern void mem_reinit();
+extern void meminit();
+extern FILE *pathopen();
+extern void p_flush();
+extern void p_num();
+extern void p_str();
+extern void p_setout();
+extern void rmlocal();
+extern char *strrchr();
+extern void settemp();
+extern char *simple();
+extern void stdsigs();
+extern void tdystak();
+extern char *valup();
+
+static void exfile();
+static void pr_prompt();
+static void chkmail();
+
+extern char **environ;
+
+
+/* The following is defined for fixcmd */
+
+static struct stat lastmail;
+static long mailtime;
+static BOOL beenhere = 0;
+static int euserid;
+static int egroupid;
+
+main(c, v)
+int c;
+register char *v[];
+{
+ FILE fd;
+ register char *sim;
+ register int rsflag=1; /* local restricted flag */
+#ifdef apollo
+ extern char pm_$unix_env ;
+ extern FILE *_iobmax;
+ pm_$unix_env = -1;
+ _iobmax = _iob + 20;
+#endif /* apollo */
+ standout = stdout;
+ p_setout(stderr);
+ standin = &stdfile;
+ userid=getuid();
+ euserid=geteuid();
+ egroupid=getegid();
+ time(&mailtime);
+ stdsigs();
+ /* initialize storage allocation */
+ stakbot = 0;
+ addblok((unsigned)0);
+ /* set up memory for namenods */
+ meminit();
+ /* set names from userenv
+ * 'rsflag' is zero if SHELL variable is
+ * set in environment and contains an'r' in
+ * the simple file part of the value.
+ */
+
+ rsflag=genenv();
+ /* a shell is also restricted if argv(0) has
+ * an 'rsh' for its simple name
+ */
+ sim = simple(*v);
+ if(*sim=='-')
+ {
+ sim++;
+ login_sh = 2;
+ }
+ /* check for restricted shell */
+ if(c>0 && gmatch(sim,"*rsh"))
+ rsflag=0;
+ /* look for options */
+ /* dolc is $# */
+ dolc=arg_opts(c,v);
+ dolv=v+c-dolc--;
+ dolv[0] = v[0];
+ if(dolc < 1)
+ on_option(STDFLG);
+ if(is_option(STDFLG|CFLAG)==0)
+ {
+ dolc--;
+ dolv++;
+ }
+ /* set[ug]id scripts run with the -p flag */
+ if(userid!=euserid || getgid()!=egroupid)
+ {
+#ifdef BSD_4_2
+ /* careful of #! setuid scripts with name beginning with - */
+ if(login_sh && strcmp(v[0],v[1])==0)
+ error(prohibited);
+#endif /* BSD_4_2 */
+ assign(PATHNOD,defpath);
+ on_option(PRIVM);
+ }
+ if(is_option(RSHFLG))
+ {
+ rsflag = 0;
+ off_option(RSHFLG);
+ }
+ /*
+ * return here for shell file execution
+ * but not for parenthesis subshells
+ */
+ setjmp(subshell);
+ cmdadr=dolv[0]; /* cmdadr is $0 */
+ /* set pidname '$$' */
+ movstr(itos(ppid=getpid()),pidadr);
+ srand(ppid);
+ ppid = getppid();
+ settemp(pidadr);
+ if((beenhere++)==0)
+ {
+ int prof = !is_option(PRIVM);
+ /* decide whether shell is interactive */
+ if(is_option(ONEFLG|CFLAG)==0 && is_option(STDFLG) && isatty(0) &&
+ isatty(2))
+ on_option(INTFLG);
+ if(ppid==1)
+ login_sh++;
+ if(login_sh >= 2)
+ {
+ /* ? profile */
+ login_sh += 2;
+#ifdef JOBS
+# ifdef BSD
+ init_jobs(1);
+# endif /* BSD */
+# ifdef SXT
+ init_jobs(1);
+# endif /* SXT */
+#endif /* JOBS */
+ /* system profile */
+ if((input=pathopen(sysprofile)) != NULL)
+ {
+ exfile(TTYFLG); /* file exists */
+ fclose(input);
+ }
+ if(prof && (input=pathopen(mactry(profile))) != NULL)
+ {
+ exfile(TTYFLG);
+ states &= ~TTYFLG;
+ fclose(input);
+ }
+ }
+ /* make sure PWD is set up correctly */
+ if(getpwd(1))
+ attrib(PWDNOD,N_EXPORT);
+ if(prof)
+ {
+ if(sim = valup(ENVNOD))
+ if(*(sim = mactry(sim)) == 0)
+ sim = 0;
+ }
+ else
+ sim = suid_profile;
+ if(sim && (input = pathopen(sim)) != NULL)
+ {
+ exfile(TTYFLG);
+ states &= ~TTYFLG;
+ fclose(input);
+ }
+ if(rsflag==0)
+ on_option(RSHFLG);
+ /* open input file if specified */
+ if(comdiv)
+ {
+ estabf(comdiv,&fd);
+ }
+ else
+ {
+ sim = cmdadr;
+ cmdadr = v[0];
+ if(is_option(STDFLG))
+ input = stdin;
+ else
+ {
+#ifdef VFORK
+ char *sp = sim;
+ /* avoid path search if we already have the
+ * path name in the environment
+ */
+ if(strcmp(sim,simple(*environ))==0)
+ sp = (*environ)+2;
+#endif /* VFORK */
+#ifdef SUID_EXEC
+ /* open stream should have been passed into shell */
+ if(gmatch(sim,devfdNN))
+ {
+ struct stat statb;
+ int fd = atoi(sim+8);
+ if(fstat(fd,&statb)<0)
+ failed(cmdadr,badopen);
+ input = fdopen(fd,"r");
+ sim = cmdadr;
+ off_option(EXECPR|READPR);
+ }
+ else
+#endif /* SUID_EXEC */
+#ifdef VFORK
+ if((input=pathopen(sp))==NULL)
+#else
+ if((input=pathopen(sim))==NULL)
+ /* for compatibility with bsh */
+ if((input=chkopen(sim))==NULL)
+#endif /* VFORK */
+ failed(sim,badopen);
+ /* eliminate local aliases and functions */
+ gscan_some(rmlocal,alias,N_EXPORT,0);
+ gscan_some(rmlocal,prnames,N_EXPORT,0);
+ }
+ cmdadr = sim;
+ comdiv--;
+#ifdef ACCT
+ initacct();
+ if(fileno(input) != 0)
+ preacct(cmdadr);
+#endif /* ACCT */
+ }
+ }
+#ifdef pdp11
+ else
+ *execargs=(char *) dolv; /* for `ps' cmd */
+#endif /* pdp11 */
+ states |= is_option(INTFLG);
+ exfile(0);
+ if(states&PROMPT)
+ newline();
+ done(0);
+}
+
+static void exfile(prof)
+register int prof;
+{
+ long curtime;
+ TREPTR t;
+ register FILE *fp = input;
+ register struct fixcmd *fixp;
+ register int fno;
+ unsigned execflags;
+ /* move input */
+ if(fisopen(fp) && (fno=fileno(fp))!=F_STRING)
+ {
+ if(fno > 0)
+ {
+ fp = input = frenumber(fp,INIO);
+ setbuf(fp,(char*)_sibuf);
+ if(prof==0)
+ setbuf(stdin,NIL);
+ }
+ /* if stdin is a pipe it must be unbuffered */
+ else
+ setbuf(fp,ispipe(fp)?NIL:(char*)_sibuf);
+ }
+ if(states&INTFLG)
+ {
+ if(isnull(PS1NOD))
+ assign(PS1NOD, (euserid?stdprompt:supprompt));
+ states |= TTYFLG|PROMPT;
+ ignsig(SIGTERM);
+ hist_open();
+ if(fc_fix)
+ on_option(FIXFLG);
+#ifdef JOBS
+# ifdef BSD
+ if(login_sh<=1)
+ init_jobs(0);
+# endif /* BSD */
+# ifdef SXT
+ if(login_sh<=1)
+ init_jobs(0);
+# endif /* SXT */
+#endif /* JOBS */
+ }
+ else
+ {
+ if(prof)
+ states |= prof;
+ else
+ {
+ off_option(EDITVI|EMACS|GMACS);
+ on_option(HASHALL|INPROC);
+ }
+ states &= ~(PROMPT|MONITOR);
+ off_option(FIXFLG);
+ }
+ fixp = fc_fix;
+ if(setjmp(errshell) && prof)
+ {
+ fclose(fp);
+ return;
+ }
+ /* error return here */
+ freturn = (jmp_buf*)errshell;
+ loopcnt=peekc=peekn=0;
+ iopend=0;
+ linked = 0;
+ if(fp!=NULL)
+ initf(fp);
+ if(feof(fp))
+ goto eof_or_error;
+ /* command loop */
+ while(1)
+ {
+ tdystak((STKPTR)0);
+ stakchk(); /* may reduce sbrk */
+ exitset();
+ states &= ~(ERRFLG|READPR|RWAIT|MONITOR);
+ states |= is_option(READPR)|WAITING|ERRFLG;
+ /* -eim flags don't apply to profiles */
+ if(prof)
+ states &= ~(INTFLG|ERRFLG|MONITOR);
+ p_setout(stderr);
+ if((states&PROMPT) && standin->fstak==0 && !feof(fp))
+ {
+ register char *mail;
+#ifdef JOBS
+ /* allow children to be stopped*/
+ states &= ~(MONITOR|NONSTOP);
+ states |= is_option(MONITOR);
+ list_jobs(N_FLAG);
+#endif /* JOBS */
+ if((mail=valup(MAILPNOD)) || (mail=valup(MAILNOD)))
+ {
+ time(&curtime);
+ if ((curtime - mailtime) >= mailchk)
+ {
+ chkmail(mail);
+ mailtime = curtime;
+ }
+ }
+ if(fixp)
+ hist_eof();
+ pr_prompt(mactry(valup(PS1NOD)));
+ /* sets timeout for command entry */
+#if TIMEOUT!=0
+ if(timeout <= 0 || timeout > TIMEOUT)
+ timeout = TIMEOUT;
+#endif
+ if(timeout>0)
+ alarm((unsigned)timeout);
+ standin->flin = 1;
+ }
+ trapnote=0;
+ peekc=readc();
+ if(feof(fp) || ferror(fp))
+ {
+ eof_or_error:
+ if((states&PROMPT) && standin->fstak==0 && ferror(fp)==0)
+ {
+ clearerr(fp);
+ if(is_option(NOEOF) && !ferror(output))
+ {
+ p_str(logout,NL);
+ continue;
+ }
+#ifdef JOBS
+ else if(close_jobs()<0)
+ continue;
+#endif /* JOBS */
+ hist_close();
+ }
+ return;
+ }
+ if(timeout>0)
+ alarm(0);
+ if((states&PROMPT) && fixp)
+ {
+ hist_eof();
+ putc(peekc,fixp->fixfd);
+ }
+ states |= is_option(FIXFLG);
+ states &= ~ WAITING;
+ t = cmd(NL,MTFLG);
+ if(fixp)
+ hist_flush();
+ if(t)
+ {
+ execflags = ERRFLG;
+ /* sh -c simple-command may not have to fork */
+ if(prof==0 && is_option(CFLAG) && (t->tretyp&COMMSK)==TCOM
+ && nextchar(fp)==0)
+ {
+ execflags |= 1;
+ }
+ execute(t,execflags);
+ }
+ }
+}
+
+/*
+ * if there is pending input, the prompt is not printed.
+ * prints PS2 if flag is zero otherwise PS3
+ */
+
+void chkpr(flag)
+register int flag;
+{
+ if(flag || (states&PROMPT) && standin->fstak==0)
+ {
+ /* if characters are in input buffer don't issue prompt */
+ if((flag?stdin:input)->_cnt > 0)
+ return;
+ p_setout(stderr);
+ fputs(valup(flag?PS3NOD:PS2NOD),output);
+ }
+}
+
+
+
+/* prints out messages if files in list have been modified since last call */
+static void chkmail(files)
+char *files;
+{
+ register char *cp,*sp,*qp;
+ register char save;
+ struct stat statb;
+ if(*(cp=files) == 0)
+ return;
+ sp = cp;
+ do
+ {
+ /* skip to : or end of string saving first '?' */
+ for(qp=0;*sp && *sp != ':';sp++)
+ if((*sp == '?' || *sp=='%') && qp == 0)
+ qp = sp;
+ save = *sp;
+ *sp = 0;
+ /* change '?' to end-of-string */
+ if(qp)
+ *qp = 0;
+ gchain = NULL;
+ do
+ {
+ /* see if time has been modified since last checked
+ * and the access time <= the modification time
+ */
+ if(stat(cp,&statb) >= 0 && statb.st_mtime >= mailtime
+ && statb.st_atime <= statb.st_mtime)
+ {
+ /* check for directory */
+ if(gchain==NULL && (statb.st_mode&S_IFMT)==S_IFDIR)
+ {
+ /* generate list of directory entries */
+ f_complete(cp,"/*");
+ }
+ else
+ {
+ /*
+ * If the file has shrunk,
+ * or if the size is zero
+ * then don't print anything
+ */
+ if(statb.st_size &&
+ ( statb.st_ino != lastmail.st_ino
+ || statb.st_dev != lastmail.st_dev
+ || statb.st_size > lastmail.st_size))
+ {
+ /* save and restore $_ */
+ char *save = lastarg;
+ lastarg = cp;
+ p_str(mactry(qp==0?mailmsg:qp+1),NL);
+ lastarg = save;
+ }
+ lastmail = statb;
+ break;
+ }
+ }
+ if(gchain)
+ {
+ cp = gchain->argval;
+ gchain = gchain->argchn;
+ }
+ else
+ cp = NULL;
+ }
+ while(cp);
+ if(qp)
+ *qp = '?';
+ *sp++ = save;
+ cp = sp;
+ }
+ while(save);
+ tdystak((STKPTR)0);
+}
+
+/*
+ * print the primary prompt
+ */
+
+static void pr_prompt(string)
+register char *string;
+{
+ register char *cp;
+ register int c;
+ static short cmdno;
+#ifdef BSD
+ int mode;
+#include <sys/ioctl.h>
+ mode = LFLUSHO;
+ ioctl(fileno(output),TIOCLBIC,&mode);
+#endif /* BSD */
+ p_flush();
+ p_setout(stderr);
+ for(cp=string;c= *cp;cp++)
+ {
+ if(c==FC_CHAR)
+ {
+ /* look at next character */
+ c = *++cp;
+ /* print out line number if not !! */
+ if(c!= FC_CHAR)
+ p_num(fc_fix?fc_fix->fixind:++cmdno,0);
+ if(c==0)
+ break;
+ }
+ putc(c,output);
+ }
+#if VSH || ESH
+ *output->_ptr = 0;
+ /* prompt flushed later */
+#else
+ p_flush();
+#endif
+}
+
+/* make sure PWD is set up correctly */
+
+/*
+ * Return the value of the PWD variable
+ * Invokes /bin/pwd if necessary
+ * If mode non-zero, then PWD must have same device/inode as dot
+ */
+
+char *getpwd(mode)
+{
+ register char *sim;
+ register int count = 0;
+ while((sim=valup(PWDNOD))==NULL || *sim==0 || (mode&&!eq_inode(sim,dot)))
+ {
+ if(count++ > 0)
+ return(NULL);
+ if((sim=valup(HOME)) && *sim=='/' && eq_inode(sim,dot))
+ {
+ fassign(PWDNOD,sim);
+ break;
+ }
+ else
+ {
+#ifdef apollo
+ char buff[BUFSIZ+1];
+ extern char *getcwd();
+ sim=getcwd(buff+1,BUFSIZ);
+ if(buff[1]=='/' && buff[2]=='/')
+ {
+ buff[0]='/';
+ buff[1] = 'n';
+ sim = buff;
+ }
+ fassign(PWDNOD,sim);
+#else
+ /* even restricted shells can pwd */
+ optflag savflags = flags;
+ off_option(RSHFLG);
+ execexp(setpwd,(FILE*)0);
+ flags = savflags;
+#endif /* apollo */
+ }
+ }
+ return(sim);
+}
+
+
+/*
+ * This version of access checks against effective uid/gid
+ */
+
+access(name, mode)
+register char *name;
+register int mode;
+{
+ struct stat statb;
+ if (stat(name, &statb) == 0)
+ {
+ if(mode == 0)
+ return(mode);
+ else if(euserid == 0)
+ {
+ if((statb.st_mode&S_IFMT) != S_IFREG || mode != 1)
+ return(0);
+ /* root needs execute permission for someone */
+ mode = (S_IEXEC|(S_IEXEC>>3)|(S_IEXEC>>6));
+ }
+ else if(euserid == statb.st_uid)
+ mode <<= 6;
+ else if(egroupid == statb.st_gid)
+ mode <<= 3;
+#ifdef BSD
+# ifdef BSD_4_2
+ /* in BSD_4_2 you can be in several groups */
+ else
+ {
+ int groups[NGROUPS];
+ register int n;
+ n = getgroups(NGROUPS,groups);
+ while(--n >= 0)
+ {
+ if(groups[n] == statb.st_gid)
+ {
+ mode <<= 3;
+ break;
+ }
+ }
+ }
+# endif /* BSD_4_2 */
+#endif /* BSD */
+ if(statb.st_mode & mode)
+ return(0);
+ }
+ return(-1);
+}
+
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