minix/commands/awk/l.c

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C
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2005-04-21 16:53:53 +02:00
/*
* a small awk clone
*
* (C) 1989 Saeko Hirabauashi & Kouichi Hirabayashi
*
* Absolutely no warranty. Use this software with your own risk.
*
* Permission to use, copy, modify and distribute this software for any
* purpose and without fee is hereby granted, provided that the above
* copyright and disclaimer notice.
*
* This program was written to fit into 64K+64K memory of the Minix 1.2.
*/
#include <stdio.h>
#include <ctype.h>
#include "awk.h"
extern char *srcprg; /* inline program */
extern FILE *pfp; /* program file */
int sym; /* lexical token */
int sym1; /* auxiliary lexical token */
int regexflg; /* set by parser (y.c) to indicate parsing REGEXPR */
int funflg; /* set by parser (y.c) to indicate parsing FUNCTION */
int printflg; /* set by parser (y.c) to indicate parsing PRINT */
int getlineflg; /* set by parser (y.c) to indicate parsing GETLINE */
char text[BUFSIZ]; /* lexical word */
char line[BUFSIZ]; /* program line for error message (ring buffer) */
char *linep = line; /* line pointer */
char funnam[128]; /* function name for error message */
int lineno = 1;
lex()
{
int c, d;
char *s;
if (regexflg)
return sym = scanreg();
next:
while ((c = Getc()) == ' ' || c == '\t')
;
while (c == '#')
for (c = Getc(); c != '\n'; c = Getc())
;
switch (c) {
case '\\':
if ((c = Getc()) == '\n') {
lineno++;
goto next;
}
break;
case '\n':
lineno++;
break;
}
switch (c) {
case EOF: return sym = 0;
case '+': return sym = follow2('=', '+', ADDEQ, INC, ADD);
case '-': return sym = follow2('=', '-', SUBEQ, DEC, SUB);
case '*': return sym = follow('=', MULTEQ, MULT);
case '/': return sym = follow('=', DIVEQ, DIV);
case '%': return sym = follow('=', MODEQ, MOD);
case '^': return sym = follow('=', POWEQ, POWER);
case '=': return sym = follow('=', EQ, ASSIGN);
case '!': return sym = follow2('=', '~', NE, NOMATCH, NOT);
case '&': return sym = follow('&', AND, BINAND);
case '|': sym = follow('|', OR, BINOR);
if (printflg && sym == BINOR)
sym = R_POUT;
return sym;
case '<': sym = follow2('=', '<', LE, SHIFTL, LT);
if (getlineflg && sym == LT)
sym = R_IN;
return sym;
case '>': sym = follow2('=', '>', GE, SHIFTR, GT);
if (printflg) {
switch (sym) {
case GT: sym = R_OUT; break;
case SHIFTR: sym = R_APD; break;
}
}
return sym;
case '~': return sym = MATCH; break;
case ';': case '\n': return sym = EOL;
}
if (isalpha(c) || c == '_') {
for (s = text; isalnum(c) || c == '_'; ) {
*s++ = c; c = Getc();
}
Ungetc(c);
*s = '\0';
if ((d = iskeywd(text)) == 0 &&
(d = isbuiltin(text, &sym1)) == 0) {
if (c == '(')
return sym = CALL;
else if (funflg) {
if ((sym1 = isarg(text)) != -1)
return sym = ARG;
}
}
return sym = d ? d : IDENT;
}
else if (c == '.' || (isdigit(c))) {
Ungetc(c);
return sym = scannum(text); /* NUMBER */
}
else if (c == '"')
return sym = scanstr(text); /* STRING */
return sym = c;
}
static
follow(c1, r1, r2)
{
register int c;
if ((c = Getc()) == c1)
return r1;
else {
Ungetc(c);
return r2;
}
}
static
follow2(c1, c2, r1, r2, r3)
{
register int c;
if ((c = Getc()) == c1)
return r1;
else if (c == c2)
return r2;
else {
Ungetc(c);
return r3;
}
}
static
iskeywd(s) char *s;
{
static struct { char *kw; int token; } tab[] = {
"BEGIN", BEGIN,
"END", END,
"break", BREAK,
"continue", CONTIN,
"delete", DELETE,
"do", DO,
"else", ELSE,
"exit", EXIT,
"for", FOR,
"func", FUNC,
"function", FUNC,
"getline", GETLINE,
"if", IF,
"in", IN,
"next", NEXT,
"print", PRINT,
"printf", PRINTF,
"return", RETURN,
"sprint", SPRINT,
"sprintf", SPRINTF,
"while", WHILE,
"", 0, 0
};
register int i;
for (i = 0; tab[i].token; i++)
if (strcmp(tab[i].kw, s) == 0)
break;
return tab[i].token;
}
static
isbuiltin(s, p) char *s; int *p;
{
static struct { char *kw; int type; int token; } tab[] = {
"atan2", MATHFUN, ATAN2,
"close", STRFUN, CLOSE,
"cos", MATHFUN, COS,
"exp", MATHFUN, EXP,
"gsub", SUBST, RGSUB,
"index", STRFUN, INDEX,
"int", MATHFUN, INT,
"length", STRFUN, LENGTH,
"log", MATHFUN, LOG,
"match", STRFUN, RMATCH,
"sin", MATHFUN, SIN,
"sqrt", MATHFUN, SQRT,
"rand", MATHFUN, RAND,
"srand", MATHFUN, SRAND,
"split", STRFUN, SPLIT,
"sub", SUBST, RSUB,
"substr", STRFUN, SUBSTR,
"system", STRFUN, SYSTEM,
"", 0, 0
};
register int i;
for (i = 0; tab[i].token; i++)
if (strcmp(tab[i].kw, s) == 0)
break;
*p = tab[i].token;
return tab[i].type;
}
static
scannum(s) char *s;
{
register int c;
char *strchr();
if ((c = Getc()) && strchr("+-", c) != NULL) {
*s++ = c; c = Getc();
}
while (isdigit(c)) {
*s++ = c; c = Getc();
}
if (c == '.') {
*s++ = c; c = Getc();
while (isdigit(c)) {
*s++ = c; c = Getc();
}
}
if (c && strchr("eE", c) != NULL) {
*s++ = c; c = Getc();
if (c && strchr("+-", c) != NULL) {
*s++ = c; c = Getc();
}
while (isdigit(c)) {
*s++ = c; c = Getc();
}
}
*s = '\0';
Ungetc(c);
return NUMBER;
}
static
scanstr(s) char *s;
{
register int c, i, j;
for (c = Getc(); c != EOF & c != '"'; ) {
if (c == '\\') {
switch (c = Getc()) {
case 'b': c = '\b'; break;
case 'f': c = '\f'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
default:
if (isdigit(c)) {
for (i = j = 0; i < 3 && isdigit(c); c = Getc(), i++)
j = j * 8 + c - '0';
Ungetc(c);
c = j;
}
break;
}
}
*s++ = c;
if (isKanji(c))
*s++ = Getc();
c = Getc();
}
*s = '\0';
return STRING;
}
static
scanreg()
{
register int c;
register char *s;
for (s = text; (c = Getc()) != '/'; )
if (c == '\n')
error("newline in regular expression");
else {
if (isKanji(c) || c == '\\') {
*s++ = c; c = Getc();
}
*s++ = c;
}
*s = '\0';
return REGEXP;
}
isarrayindex()
{
int c, c2;
next:
while ((c = Getc()) == ' ' || c == '\t')
;
if (c == '\\') {
if ((c2 = Getc()) == '\n') {
lineno++;
goto next;
}
Ungetc(c2);
}
if (c != '[') Ungetc(c);
return (c == '[');
}
#define UNGET_DEPTH 2
static int unget[UNGET_DEPTH], unget_depth;
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Ungetc(c)
{
if (unget_depth == UNGET_DEPTH) error("unget buffer overflow");
unget[unget_depth++] = c;
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if (linep > line) {
if (--linep < line)
linep == line + BUFSIZ - 1;
}
}
Getc()
{
register int c;
char *s, *t;
if (unget_depth > 0)
c = unget[--unget_depth];
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else if (srcprg)
c = *srcprg ? *srcprg++ : EOF;
else
c = fgetc(pfp);
#if 0
if (linep - line == BUFSIZ) {
printf("!!!\n");
for (s = line; *s != '\n' && ((s - line) <BUFSIZ); s++)
;
printf("***(%d)***\n", *s);
for (t = line; s < linep; )
*t++ = *++s;
}
#endif
*linep++ = c;
if ((linep - line) == BUFSIZ)
linep = line;
return c;
}