add directory study
This commit is contained in:
gohigh
369
study/linux-travel/MINIX-1.5/1.5/Source/commands/bawk/bawkpat.c
Normal file
369
study/linux-travel/MINIX-1.5/1.5/Source/commands/bawk/bawkpat.c
Normal file
@@ -0,0 +1,369 @@
|
||||
/*
|
||||
* Bawk regular expression compiler/interpreter
|
||||
*/
|
||||
#include <ctype.h>
|
||||
#include <stdio.h>
|
||||
#include "bawk.h"
|
||||
|
||||
re_compile( patbuf )
|
||||
char *patbuf; /* where to put compiled pattern */
|
||||
{
|
||||
/*
|
||||
* Compile a regular expression from current input file
|
||||
* into the given pattern buffer.
|
||||
*/
|
||||
int c, /* Current character */
|
||||
o; /* Temp */
|
||||
char *patptr, /* destination string pntr */
|
||||
*lp, /* Last pattern pointer */
|
||||
*spp, /* Save beginning of pattern */
|
||||
delim, /* pattern delimiter */
|
||||
*cclass(); /* Compile class routine */
|
||||
|
||||
lp = patptr = patbuf;
|
||||
delim = getcharacter();
|
||||
|
||||
while ( (c = getcharacter()) != -1 && c != delim )
|
||||
{
|
||||
/*
|
||||
* STAR, PLUS and MINUS are special.
|
||||
*/
|
||||
if (c == '*' || c == '+' || c == '-') {
|
||||
if (patptr == patbuf ||
|
||||
(o=patptr[-1]) == BOL ||
|
||||
o == EOL ||
|
||||
o == STAR ||
|
||||
o == PLUS ||
|
||||
o == MINUS)
|
||||
error( "illegal occurrance op", RE_ERROR );
|
||||
*patptr++ = ENDPAT;
|
||||
*patptr++ = ENDPAT;
|
||||
spp = patptr; /* Save pattern end */
|
||||
while (--patptr > lp) /* Move pattern down... */
|
||||
*patptr = patptr[-1]; /* one byte */
|
||||
*patptr = (c == '*') ? STAR :
|
||||
(c == '-') ? MINUS : PLUS;
|
||||
patptr = spp; /* Restore pattern end */
|
||||
continue;
|
||||
}
|
||||
/*
|
||||
* All the rest.
|
||||
*/
|
||||
lp = patptr; /* Remember start */
|
||||
switch(c) {
|
||||
|
||||
case '^':
|
||||
*patptr++ = BOL;
|
||||
break;
|
||||
|
||||
case '$':
|
||||
*patptr++ = EOL;
|
||||
break;
|
||||
|
||||
case '.':
|
||||
*patptr++ = ANY;
|
||||
break;
|
||||
|
||||
case '[':
|
||||
patptr = cclass( patptr );
|
||||
break;
|
||||
|
||||
case ':':
|
||||
if ( (c=getcharacter()) != -1 )
|
||||
{
|
||||
switch( tolower( c ) )
|
||||
{
|
||||
|
||||
case 'a':
|
||||
*patptr++ = ALPHA;
|
||||
break;
|
||||
|
||||
case 'd':
|
||||
*patptr++ = DIGIT;
|
||||
break;
|
||||
|
||||
case 'n':
|
||||
*patptr++ = NALPHA;
|
||||
break;
|
||||
|
||||
case ' ':
|
||||
*patptr++ = PUNCT;
|
||||
break;
|
||||
|
||||
default:
|
||||
error( "unknown ':' type", RE_ERROR );
|
||||
|
||||
}
|
||||
}
|
||||
else
|
||||
error( "no ':' type", RE_ERROR );
|
||||
break;
|
||||
|
||||
case '\\':
|
||||
c = getcharacter();
|
||||
|
||||
default:
|
||||
*patptr++ = CHAR;
|
||||
*patptr++ = c;
|
||||
}
|
||||
}
|
||||
*patptr++ = ENDPAT;
|
||||
*patptr++ = 0; /* Terminate string */
|
||||
|
||||
#ifdef DEBUG
|
||||
if ( Debug>1 )
|
||||
{
|
||||
for ( lp=patbuf; lp<patptr; ++lp )
|
||||
{
|
||||
switch ( c = *lp )
|
||||
{
|
||||
case CHAR: printf("char "); break;
|
||||
case BOL: printf("bol "); break;
|
||||
case EOL: printf("eol "); break;
|
||||
case ANY: printf("any "); break;
|
||||
case CLASS: printf("class(%d) ", *++lp); break;
|
||||
case NCLASS: printf("notclass(%d) ",*++lp); break;
|
||||
case STAR: printf("star "); break;
|
||||
case PLUS: printf("plus "); break;
|
||||
case MINUS: printf("minus "); break;
|
||||
case ALPHA: printf("alpha "); break;
|
||||
case DIGIT: printf("digit "); break;
|
||||
case NALPHA: printf("notalpha "); break;
|
||||
case PUNCT: printf("punct "); break;
|
||||
case RANGE: printf("range "); break;
|
||||
case ENDPAT: printf("endpat "); break;
|
||||
default: printf("<%c> ", c); break;
|
||||
}
|
||||
}
|
||||
printf( "\n" );
|
||||
}
|
||||
#endif
|
||||
|
||||
return patptr - patbuf;
|
||||
}
|
||||
|
||||
char *
|
||||
cclass( patbuf )
|
||||
char *patbuf; /* destination pattern buffer */
|
||||
{
|
||||
/*
|
||||
* Compile a class (within [])
|
||||
*/
|
||||
char *patptr, /* destination pattern pointer */
|
||||
*cp; /* Pattern start */
|
||||
int c, /* Current character */
|
||||
o; /* Temp */
|
||||
|
||||
patptr = patbuf;
|
||||
|
||||
if ( (c = getcharacter()) == -1 )
|
||||
error( "class terminates badly", RE_ERROR );
|
||||
else if ( c == '^')
|
||||
{
|
||||
/*
|
||||
* Class exclusion, for example: [^abc]
|
||||
* Swallow the "^" and set token type to class exclusion.
|
||||
*/
|
||||
o = NCLASS;
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* Normal class, for example: [abc]
|
||||
* push back the character and set token type to class
|
||||
*/
|
||||
ungetcharacter( c );
|
||||
o = CLASS;
|
||||
}
|
||||
*patptr++ = o;
|
||||
|
||||
cp = patptr; /* remember where byte count is */
|
||||
*patptr++ = 0; /* and initialize byte count */
|
||||
while ( (c = getcharacter()) != -1 && c!=']' )
|
||||
{
|
||||
o = getcharacter(); /* peek at next char */
|
||||
if (c == '\\') /* Store quoted chars */
|
||||
{
|
||||
if ( o == -1) /* Gotta get something */
|
||||
error( "class terminates badly", RE_ERROR );
|
||||
*patptr++ = o;
|
||||
}
|
||||
else if ( c=='-' && (patptr-cp)>1 && o!=']' && o != -1 )
|
||||
{
|
||||
c = patptr[-1]; /* Range start */
|
||||
patptr[-1] = RANGE; /* Range signal */
|
||||
*patptr++ = c; /* Re-store start */
|
||||
*patptr++ = o; /* Store end char */
|
||||
}
|
||||
else
|
||||
{
|
||||
*patptr++ = c; /* Store normal char */
|
||||
ungetcharacter( o );
|
||||
}
|
||||
}
|
||||
if (c != ']')
|
||||
error( "unterminated class", RE_ERROR );
|
||||
if ( (c = (patptr - cp)) >= 256 )
|
||||
error( "class too large", RE_ERROR );
|
||||
if ( c == 0 )
|
||||
error( "empty class", RE_ERROR );
|
||||
*cp = c; /* fill in byte count */
|
||||
|
||||
return patptr;
|
||||
}
|
||||
|
||||
match( line, pattern )
|
||||
char *line; /* line to match */
|
||||
char *pattern; /* pattern to match */
|
||||
{
|
||||
/*
|
||||
* Match the current line (in Linebuf[]), return 1 if it does.
|
||||
*/
|
||||
char *l; /* Line pointer */
|
||||
char *pmatch();
|
||||
char *next;
|
||||
int matches;
|
||||
|
||||
matches = 0;
|
||||
for (l = line; *l; l++)
|
||||
{
|
||||
if ( next = pmatch(line, l, pattern) )
|
||||
{
|
||||
l = next - 1;
|
||||
++matches;
|
||||
#ifdef DEBUG
|
||||
if ( Debug )
|
||||
printf( "match!\n" );
|
||||
#endif
|
||||
}
|
||||
}
|
||||
|
||||
return matches;
|
||||
}
|
||||
|
||||
char *
|
||||
pmatch(linestart, line, pattern)
|
||||
char *linestart; /* start of line to match */
|
||||
char *line; /* (partial) line to match */
|
||||
char *pattern; /* (partial) pattern to match */
|
||||
{
|
||||
char *l; /* Current line pointer */
|
||||
char *p; /* Current pattern pointer */
|
||||
char c; /* Current character */
|
||||
char *e; /* End for STAR and PLUS match */
|
||||
int op; /* Pattern operation */
|
||||
int n; /* Class counter */
|
||||
char *are; /* Start of STAR match */
|
||||
|
||||
l = line;
|
||||
|
||||
#ifdef DEBUG
|
||||
if (Debug > 1)
|
||||
printf("pmatch(\"%s\")\n", line);
|
||||
#endif
|
||||
|
||||
p = pattern;
|
||||
while ((op = *p++) != ENDPAT) {
|
||||
|
||||
#ifdef DEBUG
|
||||
if (Debug > 1)
|
||||
printf("byte[%d] = 0%o, '%c', op = 0%o\n",
|
||||
l-line, *l, *l, op);
|
||||
#endif
|
||||
|
||||
switch(op) {
|
||||
|
||||
case CHAR:
|
||||
if ( *l++ != *p++)
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case BOL:
|
||||
if (l != linestart)
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case EOL:
|
||||
if (*l != '\0')
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case ANY:
|
||||
if (*l++ == '\0')
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case DIGIT:
|
||||
if ((c = *l++) < '0' || (c > '9'))
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case ALPHA:
|
||||
c = tolower( *l++ );
|
||||
if (c < 'a' || c > 'z')
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case NALPHA:
|
||||
c = tolower(*l++);
|
||||
if (c >= 'a' && c <= 'z')
|
||||
break;
|
||||
else if (c < '0' || c > '9')
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case PUNCT:
|
||||
c = *l++;
|
||||
if (c == 0 || c > ' ')
|
||||
return 0;
|
||||
break;
|
||||
|
||||
case CLASS:
|
||||
case NCLASS:
|
||||
c = *l++;
|
||||
n = *p++ & 0377;
|
||||
do {
|
||||
if (*p == RANGE) {
|
||||
p += 3;
|
||||
n -= 2;
|
||||
if (c >= p[-2] && c <= p[-1])
|
||||
break;
|
||||
}
|
||||
else if (c == *p++)
|
||||
break;
|
||||
} while (--n > 1);
|
||||
if ((op == CLASS) == (n <= 1))
|
||||
return 0;
|
||||
if (op == CLASS)
|
||||
p += n - 2;
|
||||
break;
|
||||
|
||||
case MINUS:
|
||||
e = pmatch(linestart,l,p);/* Look for a match */
|
||||
while (*p++ != ENDPAT); /* Skip over pattern */
|
||||
if (e) /* Got a match? */
|
||||
l = e; /* Yes, update string */
|
||||
break; /* Always succeeds */
|
||||
|
||||
case PLUS: /* One or more ... */
|
||||
if ((l = pmatch(linestart,l,p)) == 0)
|
||||
return 0; /* Gotta have a match */
|
||||
case STAR: /* Zero or more ... */
|
||||
are = l; /* Remember line start */
|
||||
while (*l && (e = pmatch(linestart,l,p)))
|
||||
l = e; /* Get longest match */
|
||||
while (*p++ != ENDPAT); /* Skip over pattern */
|
||||
while (l >= are) { /* Try to match rest */
|
||||
if (e = pmatch(linestart,l,p))
|
||||
return e;
|
||||
--l; /* Nope, try earlier */
|
||||
}
|
||||
return 0; /* Nothing else worked */
|
||||
|
||||
default:
|
||||
fprintf( stderr, "bad op code %d\n", op );
|
||||
error( "can't happen -- match", RE_ERROR );
|
||||
}
|
||||
}
|
||||
return l;
|
||||
}
|
||||
Reference in New Issue
Block a user