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C/C++ Source or Header  |  1979-01-12  |  2.3 KB  |  125 lines
  1. #
  2. /*
  3.  * UNIX shell
  4.  *
  5.  * S. R. Bourne
  6.  * Bell Telephone Laboratories
  7.  *
  8.  */
  9.  
  10. #include    "defs.h"
  11. #include    "sym.h"
  12.  
  13.  
  14. /* ========    character handling for command lines    ========*/
  15.  
  16.  
  17. word()
  18. {
  19.     REG CHAR    c, d;
  20.     REG CHAR    *argp=locstak()+BYTESPERWORD;
  21.     INT        alpha=1;
  22.  
  23.     wdnum=0; wdset=0;
  24.  
  25.     WHILE (c=nextc(0), space(c)) DONE
  26.     IF !eofmeta(c)
  27.     THEN    REP    IF c==LITERAL
  28.             THEN    *argp++=(DQUOTE);
  29.                 WHILE (c=readc()) ANDF c!=LITERAL
  30.                 DO *argp++=(c|QUOTE); chkpr(c) OD
  31.                 *argp++=(DQUOTE);
  32.             ELSE    *argp++=(c);
  33.                 IF c=='=' THEN wdset |= alpha FI
  34.                 IF !alphanum(c) THEN alpha=0 FI
  35.                 IF qotchar(c)
  36.                 THEN    d=c;
  37.                     WHILE (*argp++=(c=nextc(d))) ANDF c!=d
  38.                     DO chkpr(c) OD
  39.                 FI
  40.             FI
  41.         PER (c=nextc(0), !eofmeta(c)) DONE
  42.         argp=endstak(argp);
  43.         IF !letter(argp->argval[0]) THEN wdset=0 FI
  44.  
  45.         peekc=c|MARK;
  46.         IF argp->argval[1]==0 ANDF (d=argp->argval[0], digit(d)) ANDF (c=='>' ORF c=='<')
  47.         THEN    word(); wdnum=d-'0';
  48.         ELSE    /*check for reserved words*/
  49.             IF reserv==FALSE ORF (wdval=syslook(argp->argval,reserved))==0
  50.             THEN    wdarg=argp; wdval=0;
  51.             FI
  52.         FI
  53.  
  54.     ELIF dipchar(c)
  55.     THEN    IF (d=nextc(0))==c
  56.         THEN    wdval = c|SYMREP;
  57.         ELSE    peekc = d|MARK; wdval = c;
  58.         FI
  59.     ELSE    IF (wdval=c)==EOF
  60.         THEN    wdval=EOFSYM;
  61.         FI
  62.         IF iopend ANDF eolchar(c)
  63.         THEN    copy(iopend); iopend=0;
  64.         FI
  65.     FI
  66.     reserv=FALSE;
  67.     return(wdval);
  68. }
  69.  
  70. nextc(quote)
  71.     CHAR        quote;
  72. {
  73.     REG CHAR    c, d;
  74.     IF (d=readc())==ESCAPE
  75.     THEN    IF (c=readc())==NL
  76.         THEN    chkpr(NL); d=nextc(quote);
  77.         ELIF quote ANDF c!=quote ANDF !escchar(c)
  78.         THEN    peekc=c|MARK;
  79.         ELSE    d = c|QUOTE;
  80.         FI
  81.     FI
  82.     return(d);
  83. }
  84.  
  85. readc()
  86. {
  87.     REG CHAR    c;
  88.     REG INT        len;
  89.     REG FILE    f;
  90.  
  91. retry:
  92.     IF peekc
  93.     THEN    c=peekc; peekc=0;
  94.     ELIF (f=standin, f->fnxt!=f->fend)
  95.     THEN    IF (c = *f->fnxt++)==0
  96.         THEN    IF f->feval
  97.             THEN    IF estabf(*f->feval++)
  98.                 THEN    c=EOF;
  99.                 ELSE    c=SP;
  100.                 FI
  101.             ELSE    goto retry; /* = c=readc(); */
  102.             FI
  103.         FI
  104.         IF flags&readpr ANDF standin->fstak==0 THEN prc(c) FI
  105.         IF c==NL THEN f->flin++ FI
  106.     ELIF f->feof ORF f->fdes<0
  107.     THEN    c=EOF; f->feof++;
  108.     ELIF (len=readb())<=0
  109.     THEN    close(f->fdes); f->fdes = -1; c=EOF; f->feof++;
  110.     ELSE    f->fend = (f->fnxt = f->fbuf)+len;
  111.         goto retry;
  112.     FI
  113.     return(c);
  114. }
  115.  
  116. LOCAL    readb()
  117. {
  118.     REG FILE    f=standin;
  119.     REG INT        len;
  120.  
  121.     REP    IF trapnote&SIGSET THEN newline(); sigchk() FI
  122.     PER (len=read(f->fdes,f->fbuf,f->fsiz))<0 ANDF trapnote DONE
  123.     return(len);
  124. }
  125.