BSD 4_1c_2 development

[unix-history] / usr / src / bin / sh / io.c

/*      io.c    4.1     82/05/07        */

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

#include        "defs.h"
#include        "dup.h"


/* ========     input output and file copying ======== */

initf(fd)
       UFD             fd;
{
       REG FILE        f=standin;

       f->fdes=fd; f->fsiz=((flags&(oneflg|ttyflg))==0 ? BUFSIZ : 1);
       f->fnxt=f->fend=f->fbuf; f->feval=0; f->flin=1;
       f->feof=FALSE;
}

estabf(s)
       REG STRING      s;
{
       REG FILE        f;

       (f=standin)->fdes = -1;
       f->fend=length(s)+(f->fnxt=s);
       f->flin=1;
       return(f->feof=(s==0));
}

push(af)
       FILE            af;
{
       REG FILE        f;

       (f=af)->fstak=standin;
       f->feof=0; f->feval=0;
       standin=f;
}

pop()
{
       REG FILE        f;

       IF (f=standin)->fstak
       THEN    IF f->fdes>=0 THEN close(f->fdes) FI
               standin=f->fstak;
               return(TRUE);
       ELSE    return(FALSE);
       FI
}

chkpipe(pv)
       INT             *pv;
{
       IF pipe(pv)<0 ORF pv[INPIPE]<0 ORF pv[OTPIPE]<0
       THEN    error(piperr);
       FI
}

chkopen(idf)
       STRING          idf;
{
       REG INT         rc;

       IF (rc=open(idf,0))<0
       THEN    failed(idf,badopen);
       ELSE    return(rc);
       FI
}

rename(f1,f2)
       REG INT         f1, f2;
{
       IF f1!=f2
       THEN    dup(f1|DUPFLG, f2);
               close(f1);
               IF f2==0 THEN ioset|=1 FI
       FI
}

create(s)
       STRING          s;
{
       REG INT         rc;

       IF (rc=creat(s,0666))<0
       THEN    failed(s,badcreate);
       ELSE    return(rc);
       FI
}

tmpfil()
{
       itos(serial++); movstr(numbuf,tmpnam);
       return(create(tmpout));
}

/* set by trim */
BOOL            nosubst;

copy(ioparg)
       IOPTR           ioparg;
{
       CHAR            c, *ends;
       REG CHAR        *cline, *clinep;
       INT             fd;
       REG IOPTR       iop;

       IF iop=ioparg
       THEN    copy(iop->iolst);
               ends=mactrim(iop->ioname); IF nosubst THEN iop->iofile &= ~IODOC FI
               fd=tmpfil();
               iop->ioname=cpystak(tmpout);
               iop->iolst=iotemp; iotemp=iop;
               cline=locstak();

               LOOP    clinep=cline; chkpr(NL);
                       WHILE (c = (nosubst ? readc() :  nextc(*ends)),  !eolchar(c)) DO *clinep++ = c OD
                       *clinep=0;
                       IF eof ORF eq(cline,ends) THEN break FI
                       *clinep++=NL;
                       write(fd,cline,clinep-cline);
               POOL
               close(fd);
       FI
}