sed0.c

来自「这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易」· C语言 代码 · 共 995 行 · 第 1/2 页

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include "sed.h"

struct label	*labtab = ltab;
char	CGMES[]	= "sed: Command garbled: %s\n";
char	TMMES[]	= "sed: Too much text: %s\n";
char	LTL[]	= "sed: Label too long: %s\n";
char	AD0MES[]	= "sed: No addresses allowed: %s\n";
char	AD1MES[]	= "sed: Only one address allowed: %s\n";
uchar	bittab[]  = {
		1,
		2,
		4,
		8,
		16,
		32,
		64,
		128
	};

main(int argc, char **argv)
{

	eargc = argc;
	eargv = (uchar**)argv;

	badp = &bad;
	aptr = abuf;
	hspend = holdsp;
	lab = labtab + 1;	/* 0 reserved for end-pointer */
	rep = ptrspace;
	rep->r1.ad1 = respace;
	lbend = &linebuf[LBSIZE];
	hend = &holdsp[LBSIZE];
	lcomend = &genbuf[64];
	ptrend = &ptrspace[PTRSIZE];
	reend = &respace[RESIZE];
	labend = &labtab[LABSIZE];
	lnum = 0;
	pending = 0;
	depth = 0;
	spend = linebuf;
	hspend = holdsp;
	fcode[0] = stdout;
	nfiles = 1;
	lastre = NULL;

	if(eargc == 1)
		exit(0);


	while (--eargc > 0 && (++eargv)[0][0] == '-')
		switch (eargv[0][1]) {

		case 'n':
			nflag++;
			continue;

		case 'f':
			if(eargc-- <= 0)	exit(2);

			if((fin = fopen((char*)(*++eargv), "r")) == NULL) {
				fprintf(stderr, "sed: Cannot open pattern-file: %s\n", *eargv);
				exit(2);
			}

			fcomp();
			fclose(fin);
			continue;

		case 'e':
			eflag++;
			fcomp();
			eflag = 0;
			continue;

		case 'g':
			gflag++;
			continue;

		default:
			fprintf(stderr, "sed: Unknown flag: %c\n", eargv[0][1]);
			continue;
		}


	if(compfl == 0) {
		eargv--;
		eargc++;
		eflag++;
		fcomp();
		eargv++;
		eargc--;
		eflag = 0;
	}

	if(depth) {
		fprintf(stderr, "sed: Too many {'s\n");
		exit(2);
	}

	labtab->address = rep;

	dechain();

/*	abort();	/*DEBUG*/

	if(eargc <= 0)
		execute((uchar *)NULL);
	else while(--eargc >= 0) {
		execute(*eargv++);
	}
	fclose(stdout);
	exit(0);
}
void
fcomp(void)
{

	uchar	*p, *op, *tp;
    uchar *address(uchar*);
	union reptr	*pt, *pt1;
	int	i;
	struct label	*lpt;

	compfl = 1;
	op = lastre;

	if(rline(linebuf) < 0) {
		lastre = op;
		return;
	}
	if(*linebuf == '#') {
		if(linebuf[1] == 'n')
			nflag = 1;
	}
	else {
		cp = linebuf;
		goto comploop;
	}

	for(;;) {
		if(rline(linebuf) < 0)	break;

		cp = linebuf;

comploop:
/*	fprintf(stdout, "cp: %s\n", cp);	/*DEBUG*/
		while(*cp == ' ' || *cp == '\t')	cp++;
		if(*cp == '\0' || *cp == '#')		continue;
		if(*cp == ';') {
			cp++;
			goto comploop;
		}

		p = address(rep->r1.ad1);
		if(p == badp) {
			fprintf(stderr, CGMES, linebuf);
			exit(2);
		}

		if(p == 0) {
			p = rep->r1.ad1;
			rep->r1.ad1 = 0;
		} else {
			if(p == rep->r1.ad1) {
				if(op)
					rep->r1.ad1 = op;
				else {
					fprintf(stderr, "sed: First RE may not be null\n");
					exit(2);
				}
			}
			if(*rep->r1.ad1 != CLNUM && *rep->r1.ad1 != CEND)
				op = rep->r1.ad1;
			if(*cp == ',' || *cp == ';') {
				cp++;
				if((rep->r1.ad2 = p) > reend) {
					fprintf(stderr, TMMES, linebuf);
					exit(2);
				}
				p = address(rep->r1.ad2);
				if(p == badp || p == 0) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				if(p == rep->r1.ad2)
					rep->r1.ad2 = op;
				else{
				if(*rep->r1.ad2 != CLNUM && *rep->r1.ad2 != CEND)
					op = rep->r1.ad2;
				}

			} else
				rep->r1.ad2 = 0;
		}

		if(p > reend) {
			fprintf(stderr, "sed: Too much text: %s\n", linebuf);
			exit(2);
		}

		while(*cp == ' ' || *cp == '\t')	cp++;

swit:
		switch(*cp++) {

			default:
/*fprintf(stderr, "cp = %d; *cp = %o\n", cp - linebuf, *cp);*/
				fprintf(stderr, "sed: Unrecognized command: %s\n", linebuf);
				exit(2);

			case '!':
				rep->r1.negfl = 1;
				goto swit;

			case '{':
				rep->r1.command = BCOM;
				rep->r1.negfl = !(rep->r1.negfl);
				cmpend[depth++] = &rep->r2.lb1;
				if(++rep >= ptrend) {
					fprintf(stderr, "sed: Too many commands: %s\n", linebuf);
					exit(2);
				}
				rep->r1.ad1 = p;
				if(*cp == '\0')	continue;

				goto comploop;

			case '}':
				if(rep->r1.ad1) {
					fprintf(stderr, AD0MES, linebuf);
					exit(2);
				}

				if(--depth < 0) {
					fprintf(stderr, "sed: Too many }'s\n");
					exit(2);
				}
				*cmpend[depth] = rep;

				rep->r1.ad1 = p;
				if(*cp == 0)	continue;
				goto comploop;

			case '=':
				rep->r1.command = EQCOM;
				if(rep->r1.ad2) {
					fprintf(stderr, AD1MES, linebuf);
					exit(2);
				}
				break;

			case ':':
				if(rep->r1.ad1) {
					fprintf(stderr, AD0MES, linebuf);
					exit(2);
				}

				while(*cp++ == ' ');
				cp--;


				tp = lab->asc;
				while((*tp = *cp++) && *tp != ';')
					if(++tp >= &(lab->asc[8])) {
						fprintf(stderr, LTL, linebuf);
						exit(2);
					}
				*tp = '\0';
				if(*lab->asc == 0) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}

				if(lpt = search(lab)) {
					if(lpt->address) {
						fprintf(stderr, "sed: Duplicate labels: %s\n", linebuf);
						exit(2);
					}
				} else {
					lab->chain = 0;
					lpt = lab;
					if(++lab >= labend) {
						fprintf(stderr, "sed: Too many labels: %s\n", linebuf);
						exit(2);
					}
				}
				lpt->address = rep;
				rep->r1.ad1 = p;

				continue;

			case 'a':
				rep->r1.command = ACOM;
				if(rep->r1.ad2) {
					fprintf(stderr, AD1MES, linebuf);
					exit(2);
				}
				if(*cp == '\\')	cp++;
				if(*cp++ != '\n') {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				rep->r1.re1 = p;
				p = text(rep->r1.re1);
				break;
			case 'c':
				rep->r1.command = CCOM;
				if(*cp == '\\')	cp++;
				if(*cp++ != ('\n')) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				rep->r1.re1 = p;
				p = text(rep->r1.re1);
				break;
			case 'i':
				rep->r1.command = ICOM;
				if(rep->r1.ad2) {
					fprintf(stderr, AD1MES, linebuf);
					exit(2);
				}
				if(*cp == '\\')	cp++;
				if(*cp++ != ('\n')) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				rep->r1.re1 = p;
				p = text(rep->r1.re1);
				break;

			case 'g':
				rep->r1.command = GCOM;
				break;

			case 'G':
				rep->r1.command = CGCOM;
				break;

			case 'h':
				rep->r1.command = HCOM;
				break;

			case 'H':
				rep->r1.command = CHCOM;
				break;

			case 't':
				rep->r1.command = TCOM;
				goto jtcommon;

			case 'b':
				rep->r1.command = BCOM;
jtcommon:
				while(*cp++ == ' ');
				cp--;

				if(*cp == '\0') {
					if(pt = labtab->chain) {
						while(pt1 = pt->r2.lb1)
							pt = pt1;
						pt->r2.lb1 = rep;
					} else
						labtab->chain = rep;
					break;
				}
				tp = lab->asc;
				while((*tp = *cp++) && *tp != ';')
					if(++tp >= &(lab->asc[8])) {
						fprintf(stderr, LTL, linebuf);
						exit(2);
					}
				cp--;
				*tp = '\0';
				if(*lab->asc == 0) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}

				if(lpt = search(lab)) {
					if(lpt->address) {
						rep->r2.lb1 = lpt->address;
					} else {
						pt = lpt->chain;
						while(pt1 = pt->r2.lb1)
							pt = pt1;
						pt->r2.lb1 = rep;
					}
				} else {
					lab->chain = rep;
					lab->address = 0;
					if(++lab >= labend) {
						fprintf(stderr, "sed: Too many labels: %s\n", linebuf);
						exit(2);
					}
				}
				break;

			case 'n':
				rep->r1.command = NCOM;
				break;

			case 'N':
				rep->r1.command = CNCOM;
				break;

			case 'p':
				rep->r1.command = PCOM;
				break;

			case 'P':
				rep->r1.command = CPCOM;
				break;

			case 'r':
				rep->r1.command = RCOM;
				if(rep->r1.ad2) {
					fprintf(stderr, AD1MES, linebuf);
					exit(2);
				}
				if(*cp++ != ' ') {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				rep->r1.re1 = p;
				p = text(rep->r1.re1);
				break;

			case 'd':
				rep->r1.command = DCOM;
				break;

			case 'D':
				rep->r1.command = CDCOM;
				rep->r2.lb1 = ptrspace;
				break;

			case 'q':
				rep->r1.command = QCOM;
				if(rep->r1.ad2) {
					fprintf(stderr, AD1MES, linebuf);
					exit(2);
				}
				break;

			case 'l':
				rep->r1.command = LCOM;
				break;

			case 's':
				rep->r1.command = SCOM;
				seof = *cp++;
				rep->r1.re1 = p;
				p = compile(rep->r1.re1);
				if(p == badp) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				if(p == rep->r1.re1) {
					if(op == NULL) {
						fprintf(stderr, "sed: First RE may not be null.\n");
						exit(2);
					}
					rep->r1.re1 = op;
				} else {
					op = rep->r1.re1;
				}

				if((rep->r1.rhs = p) > reend) {
					fprintf(stderr, TMMES, linebuf);
					exit(2);
				}

				if((p = compsub(rep->r1.rhs)) == badp) {
					fprintf(stderr, CGMES, linebuf);
					exit(2);
				}
				if(*cp == 'g') {
					cp++;
					rep->r1.gfl++;
				} else if(gflag)
					rep->r1.gfl++;

				if(*cp == 'p') {
					cp++;
					rep->r1.pfl = 1;
				}

				if(*cp == 'P') {
					cp++;
					rep->r1.pfl = 2;
				}

				if(*cp == 'w') {
					cp++;