BSD 3 development

[unix-history] / usr / src / cmd / sh / expand.c

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

#include        "defs.h"
#include        <sys/types.h>
#define DIRSIZ 15
#include        <sys/stat.h>
#include        <sys/dir.h>



/* globals (file name generation)
*
* "*" in params matches r.e ".*"
* "?" in params matches r.e. "."
* "[...]" in params matches character class
* "[...a-z...]" in params matches a through z.
*
*/

PROC VOID       addg();


INT     expand(as,rflg)
       STRING          as;
{
       INT             count, dirf;
       BOOL            dir=0;
       STRING          rescan = 0;
       REG STRING      s, cs;
       ARGPTR          schain = gchain;
       struct direct   entry;
       STATBUF         statb;

       IF trapnote&SIGSET THEN return(0); FI

       s=cs=as; entry.d_name[DIRSIZ-1]=0; /* to end the string */

       /* check for meta chars */
       BEGIN
          REG BOOL slash; slash=0;
          WHILE !fngchar(*cs)
          DO   IF *cs++==0
               THEN    IF rflg ANDF slash THEN break; ELSE return(0) FI
               ELIF *cs=='/'
               THEN    slash++;
               FI
          OD
       END

       LOOP    IF cs==s
               THEN    s=nullstr;
                       break;
               ELIF *--cs == '/'
               THEN    *cs=0;
                       IF s==cs THEN s="/" FI
                       break;
               FI
       POOL
       IF stat(s,&statb)>=0
           ANDF (statb.st_mode&S_IFMT)==S_IFDIR
           ANDF (dirf=open(s,0))>0
       THEN    dir++;
       FI
       count=0;
       IF *cs==0 THEN *cs++=0200 FI
       IF dir
       THEN    /* check for rescan */
               REG STRING rs; rs=cs;

               REP     IF *rs=='/' THEN rescan=rs; *rs=0; gchain=0 FI
               PER     *rs++ DONE

               WHILE read(dirf, &entry, 16) == 16 ANDF (trapnote&SIGSET) == 0
               DO      IF entry.d_ino==0 ORF
                           (*entry.d_name=='.' ANDF *cs!='.')
                       THEN    continue;
                       FI
                       IF gmatch(entry.d_name, cs)
                       THEN    addg(s,entry.d_name,rescan); count++;
                       FI
               OD
               close(dirf);

               IF rescan
               THEN    REG ARGPTR      rchain;
                       rchain=gchain; gchain=schain;
                       IF count
                       THEN    count=0;
                               WHILE rchain
                               DO      count += expand(rchain->argval,1);
                                       rchain=rchain->argnxt;
                               OD
                       FI
                       *rescan='/';
               FI
       FI

       BEGIN
          REG CHAR     c;
          s=as;
          WHILE c = *s
          DO   *s++=(c&STRIP?c:'/') OD
       END
       return(count);
}

gmatch(s, p)
       REG STRING      s, p;
{
       REG INT         scc;
       CHAR            c;

       IF scc = *s++
       THEN    IF (scc &= STRIP)==0
               THEN    scc=0200;
               FI
       FI
       SWITCH c = *p++ IN

           case '[':
               {BOOL ok; INT lc;
               ok=0; lc=077777;
               WHILE c = *p++
               DO      IF c==']'
                       THEN    return(ok?gmatch(s,p):0);
                       ELIF c==MINUS
                       THEN    IF lc<=scc ANDF scc<=(*p++) THEN ok++ FI
                       ELSE    IF scc==(lc=(c&STRIP)) THEN ok++ FI
                       FI
               OD
               return(0);
               }

           default:
               IF (c&STRIP)!=scc THEN return(0) FI

           case '?':
               return(scc?gmatch(s,p):0);

           case '*':
               IF *p==0 THEN return(1) FI
               --s;
               WHILE *s
               DO  IF gmatch(s++,p) THEN return(1) FI OD
               return(0);

           case 0:
               return(scc==0);
       ENDSW
}

LOCAL VOID      addg(as1,as2,as3)
       STRING          as1, as2, as3;
{
       REG STRING      s1, s2;
       REG INT         c;

       s2 = locstak()+BYTESPERWORD;

       s1=as1;
       WHILE c = *s1++
       DO      IF (c &= STRIP)==0
               THEN    *s2++='/';
                       break;
               FI
               *s2++=c;
       OD
       s1=as2;
       WHILE *s2 = *s1++ DO s2++ OD
       IF s1=as3
       THEN    *s2++='/';
               WHILE *s2++ = *++s1 DONE
       FI
       makearg(endstak(s2));
}

makearg(args)
       REG STRING      args;
{
       args->argnxt=gchain;
       gchain=args;
}