BSD 4_4 release

[unix-history] / usr / src / old / sh / macro.c

#ifndef lint
static char sccsid[] = "@(#)macro.c     4.4 4/24/88";
#endif

#
/*
* UNIX shell
*
* S. R. Bourne
* Bell Telephone Laboratories
*
*/

#include        "defs.h"
#include        "sym.h"

LOCAL CHAR      quote;  /* used locally */
LOCAL CHAR      quoted; /* used locally */



LOCAL STRING    copyto(endch)
       REG CHAR        endch;
{
       REG CHAR        c;

       WHILE (c=getch(endch))!=endch ANDF c
       DO pushstak(c|quote) OD
       zerostak();
       IF c!=endch THEN error(badsub) FI
}

LOCAL   skipto(endch)
       REG CHAR        endch;
{
       /* skip chars up to } */
       REG CHAR        c;
       WHILE (c=readc()) ANDF c!=endch
       DO      SWITCH c IN

               case SQUOTE:    skipto(SQUOTE); break;

               case DQUOTE:    skipto(DQUOTE); break;

               case DOLLAR:    IF readc()==BRACE
                               THEN    skipto('}');
                               FI
               ENDSW
       OD
       IF c!=endch THEN error(badsub) FI
}

LOCAL   getch(endch)
       CHAR            endch;
{
       REG CHAR        d;

retry:
       d=readc();
       IF !subchar(d)
       THEN    return(d);
       FI
       IF d==DOLLAR
       THEN    REG INT c;
               IF (c=readc(), dolchar(c))
               THEN    NAMPTR          n=NIL;
                       INT             dolg=0;
                       BOOL            bra;
                       REG STRING      argp, v;
                       CHAR            idb[2];
                       STRING          id=idb;

                       IF bra=(c==BRACE) THEN c=readc() FI
                       IF letter(c)
                       THEN    argp=relstak();
                               WHILE alphanum(c) DO pushstak(c); c=readc() OD
                               zerostak();
                               n=lookup(absstak(argp)); setstak(argp);
                               v = n->namval; id = n->namid;
                               peekc = c|MARK;;
                       ELIF digchar(c)
                       THEN    *id=c; idb[1]=0;
                               IF astchar(c)
                               THEN    dolg=1; c='1';
                               FI
                               c -= '0';
                               v=((c==0) ? cmdadr : (c<=dolc) ? dolv[c] : (STRING)(dolg=0));
                       ELIF c=='$'
                       THEN    v=pidadr;
                       ELIF c=='!'
                       THEN    v=pcsadr;
                       ELIF c=='#'
                       THEN    v=dolladr;
                       ELIF c=='?'
                       THEN    v=exitadr;
                       ELIF c=='-'
                       THEN    v=flagadr;
                       ELIF bra THEN error(badsub);
                       ELSE    goto retry;
                       FI
                       c = readc();
                       IF !defchar(c) ANDF bra
                       THEN    error(badsub);
                       FI
                       argp=0;
                       IF bra
                       THEN    IF c!='}'
                               THEN    argp=relstak();
                                       IF (v==0)NEQ(setchar(c))
                                       THEN    copyto('}');
                                       ELSE    skipto('}');
                                       FI
                                       argp=absstak(argp);
                               FI
                       ELSE    peekc = c|MARK; c = 0;
                       FI
                       IF v
                       THEN    IF c!='+'
                               THEN    LOOP WHILE c = *v++
                                            DO pushstak(c|quote); OD
                                            IF dolg==0 ORF (++dolg>dolc)
                                            THEN break;
                                            ELSE v=dolv[dolg]; pushstak(SP|(*id=='*' ? quote : 0));
                                            FI
                                       POOL
                               FI
                       ELIF argp
                       THEN    IF c=='?'
                               THEN    failed(id,*argp?argp:badparam);
                               ELIF c=='='
                               THEN    IF n
                                       THEN    assign(n,argp);
                                       ELSE    error(badsub);
                                       FI
                               FI
                       ELIF flags&setflg
                       THEN    failed(id,badparam);
                       FI
                       goto retry;
               ELSE    peekc=c|MARK;
               FI
       ELIF d==endch
       THEN    return(d);
       ELIF d==SQUOTE
       THEN    comsubst(); goto retry;
       ELIF d==DQUOTE
       THEN    quoted++; quote^=QUOTE; goto retry;
       FI
       return(d);
}

STRING  macro(as)
       STRING          as;
{
       /* Strip "" and do $ substitution
        * Leaves result on top of stack
        */
       REG BOOL        savqu =quoted;
       REG CHAR        savq = quote;
       FILEHDR         fb;

       push(&fb); estabf(as);
       usestak();
       quote=0; quoted=0;
       copyto(0);
       pop();
       IF quoted ANDF (stakbot==staktop) THEN pushstak(QUOTE) FI
       quote=savq; quoted=savqu;
       return(fixstak());
}

LOCAL   comsubst()
{
       /* command substn */
       FILEBLK         cb;
       REG CHAR        d;
       REG STKPTR      savptr = fixstak();

       usestak();
       WHILE (d=readc())!=SQUOTE ANDF d
       DO pushstak(d) OD

       BEGIN
          REG STRING   argc;
          trim(argc=fixstak());
          push(&cb); estabf(argc);
       END
       BEGIN
          REG TREPTR   t = makefork(FPOU,cmd(EOFSYM,MTFLG|NLFLG));
          INT          pv[2];

          /* this is done like this so that the pipe
           * is open only when needed
           */
          chkpipe(pv);
          initf(pv[INPIPE]);
          execute(t, 0, 0, pv);
          close(pv[OTPIPE]);
       END
       tdystak(savptr); staktop=movstr(savptr,stakbot);
       WHILE d=readc() DO locstak(); pushstak(d|quote) OD
       await(0);
       WHILE stakbot!=staktop
       DO      IF (*--staktop&STRIP)!=NL
               THEN    ++staktop; break;
               FI
       OD
       pop();
}

#define CPYSIZ  512

subst(in,ot)
       INT             in, ot;
{
       REG CHAR        c;
       FILEBLK         fb;
       REG INT         count=CPYSIZ;

       push(&fb); initf(in);
       /* DQUOTE used to stop it from quoting */
       WHILE c=(getch(DQUOTE)&STRIP)
       DO pushstak(c);
          IF --count == 0
          THEN flush(ot); count=CPYSIZ;
          FI
       OD
       flush(ot);
       pop();
}

LOCAL   flush(ot)
{
       write(ot,stakbot,staktop-stakbot);
       IF flags&execpr THEN write(output,stakbot,staktop-stakbot) FI
       staktop=stakbot;
}