# /* * UNIX shell * * S. R. Bourne * Bell Telephone Laboratories * */ #include "defs.h" PROC BOOL chkid(); NAMNOD ps2nod = { NIL, NIL, ps2name}, fngnod = { NIL, NIL, fngname}, pathnod = { NIL, NIL, pathname}, ifsnod = { NIL, NIL, ifsname}, ps1nod = { &pathnod, &ps2nod, ps1name}, homenod = { &fngnod, &ifsnod, homename}, mailnod = { &homenod, &ps1nod, mailname}; NAMPTR namep = &mailnod; /* ======== variable and string handling ======== */ syslook(w,syswds) STRING w; SYSTAB syswds; { REG CHAR first; REG STRING s; REG SYSPTR syscan; syscan=syswds; first = *w; WHILE s=syscan->sysnam DO IF first == *s ANDF eq(w,s) THEN return(syscan->sysval); FI syscan++; OD return(0); } setlist(arg,xp) REG ARGPTR arg; INT xp; { WHILE arg DO REG STRING s=mactrim(arg->argval); setname(s, xp); arg=arg->argnxt; IF flags&execpr THEN prs(s); IF arg THEN blank(); ELSE newline(); FI FI OD } VOID setname(argi, xp) STRING argi; INT xp; { REG STRING argscan=argi; REG NAMPTR n; IF letter(*argscan) THEN WHILE alphanum(*argscan) DO argscan++ OD IF *argscan=='=' THEN *argscan = 0; n=lookup(argi); *argscan++ = '='; attrib(n, xp); IF xp&N_ENVNAM THEN n->namenv = n->namval = argscan; ELSE assign(n, argscan); FI return; FI FI failed(argi,notid); } replace(a, v) REG STRING *a; STRING v; { free(*a); *a=make(v); } dfault(n,v) NAMPTR n; STRING v; { IF n->namval==0 THEN assign(n,v) FI } assign(n,v) NAMPTR n; STRING v; { IF n->namflg&N_RDONLY THEN failed(n->namid,wtfailed); ELSE replace(&n->namval,v); FI } INT readvar(names) STRING *names; { FILEBLK fb; REG FILE f = &fb; REG CHAR c; REG INT rc=0; NAMPTR n=lookup(*names++); /* done now to avoid storage mess */ STKPTR rel=relstak(); push(f); initf(dup(0)); IF lseek(0,0L,1)==-1 THEN f->fsiz=1; FI LOOP c=nextc(0); IF (*names ANDF any(c, ifsnod.namval)) ORF eolchar(c) THEN zerostak(); assign(n,absstak(rel)); setstak(rel); IF *names THEN n=lookup(*names++); ELSE n=0; FI IF eolchar(c) THEN break; FI ELSE pushstak(c); FI POOL WHILE n DO assign(n, nullstr); IF *names THEN n=lookup(*names++); ELSE n=0; FI OD IF eof THEN rc=1 FI lseek(0, (long)(f->fnxt-f->fend), 1); pop(); return(rc); } assnum(p, i) STRING *p; INT i; { itos(i); replace(p,numbuf); } STRING make(v) STRING v; { REG STRING p; IF v THEN movstr(v,p=alloc(length(v))); return(p); ELSE return(0); FI } NAMPTR lookup(nam) REG STRING nam; { REG NAMPTR nscan=namep; REG NAMPTR *prev; INT LR; IF !chkid(nam) THEN failed(nam,notid); FI WHILE nscan DO IF (LR=cf(nam,nscan->namid))==0 THEN return(nscan); ELIF LR<0 THEN prev = &(nscan->namlft); ELSE prev = &(nscan->namrgt); FI nscan = *prev; OD /* add name node */ nscan=alloc(sizeof *nscan); nscan->namlft=nscan->namrgt=NIL; nscan->namid=make(nam); nscan->namval=0; nscan->namflg=N_DEFAULT; nscan->namenv=0; return(*prev = nscan); } LOCAL BOOL chkid(nam) STRING nam; { REG CHAR * cp=nam; IF !letter(*cp) THEN return(FALSE); ELSE WHILE *++cp DO IF !alphanum(*cp) THEN return(FALSE); FI OD FI return(TRUE); } LOCAL VOID (*namfn)(); namscan(fn) VOID (*fn)(); { namfn=fn; namwalk(namep); } LOCAL VOID namwalk(np) REG NAMPTR np; { IF np THEN namwalk(np->namlft); (*namfn)(np); namwalk(np->namrgt); FI } VOID printnam(n) NAMPTR n; { REG STRING s; sigchk(); IF s=n->namval THEN prs(n->namid); prc('='); prs(s); newline(); FI } LOCAL STRING staknam(n) REG NAMPTR n; { REG STRING p; p=movstr(n->namid,staktop); p=movstr("=",p); p=movstr(n->namval,p); return(getstak(p+1-ADR(stakbot))); } VOID exname(n) REG NAMPTR n; { IF n->namflg&N_EXPORT THEN free(n->namenv); n->namenv = make(n->namval); ELSE free(n->namval); n->namval = make(n->namenv); FI } VOID printflg(n) REG NAMPTR n; { IF n->namflg&N_EXPORT THEN prs(export); blank(); FI IF n->namflg&N_RDONLY THEN prs(readonly); blank(); FI IF n->namflg&(N_EXPORT|N_RDONLY) THEN prs(n->namid); newline(); FI } VOID getenv() { REG STRING *e=environ; WHILE *e DO setname(*e++, N_ENVNAM) OD } LOCAL INT namec; VOID countnam(n) NAMPTR n; { namec++; } LOCAL STRING *argnam; VOID pushnam(n) NAMPTR n; { IF n->namval THEN *argnam++ = staknam(n); FI } STRING *setenv() { REG STRING *er; namec=0; namscan(countnam); argnam = er = getstak(namec*BYTESPERWORD+BYTESPERWORD); namscan(pushnam); *argnam++ = 0; return(er); }