common.c

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于我们学习和理解

#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>
#include "common.h"
#include "comments.h"
#include "path.h"

struct strtab charcode[FONTSIZE] = {
	{4, "\\000"}, {4, "\\001"}, {4, "\\002"}, {4, "\\003"},
	{4, "\\004"}, {4, "\\005"}, {4, "\\006"}, {4, "\\007"},
	{4, "\\010"}, {4, "\\011"}, {4, "\\012"}, {4, "\\013"},
	{4, "\\014"}, {4, "\\015"}, {4, "\\016"}, {4, "\\017"},
	{4, "\\020"}, {4, "\\021"}, {4, "\\022"}, {4, "\\023"},
	{4, "\\024"}, {4, "\\025"}, {4, "\\026"}, {4, "\\027"},
	{4, "\\030"}, {4, "\\031"}, {4, "\\032"}, {4, "\\033"},
	{4, "\\034"}, {4, "\\035"}, {4, "\\036"}, {4, "\\037"},
	{1, " "}, {1, "!"}, {1, "\""}, {1, "#"},
	{1, "$"}, {1, "%"}, {1, "&"}, {1, "'"},
	{2, "\\("}, {2, "\\)"}, {1, "*"}, {1, "+"},
	{1, ","}, {1, "-"}, {1, "."}, {1, "/"},
	{1, "0"}, {1, "1"}, {1, "2"}, {1, "3"},
	{1, "4"}, {1, "5"}, {1, "6"}, {1, "7"},
	{1, "8"}, {1, "9"}, {1, ":"}, {1, ";"},
	{1, "<"}, {1, "="}, {1, ">"}, {1, "?"},
	{1, "@"}, {1, "A"}, {1, "B"}, {1, "C"},
	{1, "D"}, {1, "E"}, {1, "F"}, {1, "G"},
	{1, "H"}, {1, "I"}, {1, "J"}, {1, "K"},
	{1, "L"}, {1, "M"}, {1, "N"}, {1, "O"},
	{1, "P"}, {1, "Q"}, {1, "R"}, {1, "S"},
	{1, "T"}, {1, "U"}, {1, "V"}, {1, "W"},
	{1, "X"}, {1, "Y"}, {1, "Z"}, {1, "["},
	{2, "\\\\"}, {1, "]"}, {1, "^"}, {1, "_"},
	{1, "`"}, {1, "a"}, {1, "b"}, {1, "c"},
	{1, "d"}, {1, "e"}, {1, "f"}, {1, "g"},
	{1, "h"}, {1, "i"}, {1, "j"}, {1, "k"},
	{1, "l"}, {1, "m"}, {1, "n"}, {1, "o"},
	{1, "p"}, {1, "q"}, {1, "r"}, {1, "s"},
	{1, "t"}, {1, "u"}, {1, "v"}, {1, "w"},
	{1, "x"}, {1, "y"}, {1, "z"}, {1, "{"},
	{1, "|"}, {1, "}"}, {1, "~"}, {4, "\\177"},
	{4, "\\200"}, {4, "\\201"}, {4, "\\202"}, {4, "\\203"},
	{4, "\\204"}, {4, "\\205"}, {4, "\\206"}, {4, "\\207"},
	{4, "\\210"}, {4, "\\211"}, {4, "\\212"}, {4, "\\213"},
	{4, "\\214"}, {4, "\\215"}, {4, "\\216"}, {4, "\\217"},
	{4, "\\220"}, {4, "\\221"}, {4, "\\222"}, {4, "\\223"},
	{4, "\\224"}, {4, "\\225"}, {4, "\\226"}, {4, "\\227"},
	{4, "\\230"}, {4, "\\231"}, {4, "\\232"}, {4, "\\233"},
	{4, "\\234"}, {4, "\\235"}, {4, "\\236"}, {4, "\\237"},
	{4, "\\240"}, {4, "\\241"}, {4, "\\242"}, {4, "\\243"},
	{4, "\\244"}, {4, "\\245"}, {4, "\\246"}, {4, "\\247"},
	{4, "\\250"}, {4, "\\251"}, {4, "\\252"}, {4, "\\253"},
	{4, "\\254"}, {4, "\\255"}, {4, "\\256"}, {4, "\\257"},
	{4, "\\260"}, {4, "\\261"}, {4, "\\262"}, {4, "\\263"},
	{4, "\\264"}, {4, "\\265"}, {4, "\\266"}, {4, "\\267"},
	{4, "\\270"}, {4, "\\271"}, {4, "\\272"}, {4, "\\273"},
	{4, "\\274"}, {4, "\\275"}, {4, "\\276"}, {4, "\\277"},
	{4, "\\300"}, {4, "\\301"}, {4, "\\302"}, {4, "\\303"},
	{4, "\\304"}, {4, "\\305"}, {4, "\\306"}, {4, "\\307"},
	{4, "\\310"}, {4, "\\311"}, {4, "\\312"}, {4, "\\313"},
	{4, "\\314"}, {4, "\\315"}, {4, "\\316"}, {4, "\\317"},
	{4, "\\320"}, {4, "\\321"}, {4, "\\322"}, {4, "\\323"},
	{4, "\\324"}, {4, "\\325"}, {4, "\\326"}, {4, "\\327"},
	{4, "\\330"}, {4, "\\331"}, {4, "\\332"}, {4, "\\333"},
	{4, "\\334"}, {4, "\\335"}, {4, "\\336"}, {4, "\\337"},
	{4, "\\340"}, {4, "\\341"}, {4, "\\342"}, {4, "\\343"},
	{4, "\\344"}, {4, "\\345"}, {4, "\\346"}, {4, "\\347"},
	{4, "\\350"}, {4, "\\351"}, {4, "\\352"}, {4, "\\353"},
	{4, "\\354"}, {4, "\\355"}, {4, "\\356"}, {4, "\\357"},
	{4, "\\360"}, {4, "\\361"}, {4, "\\362"}, {4, "\\363"},
	{4, "\\364"}, {4, "\\365"}, {4, "\\366"}, {4, "\\367"},
	{4, "\\370"}, {4, "\\371"}, {4, "\\372"}, {4, "\\373"},
	{4, "\\374"}, {4, "\\375"}, {4, "\\376"}, {4, "\\377"}
};

static BOOLEAN in_string = FALSE;
int char_no = 0;
int line_no = 0;
int page_no = 0;		/* page number in a document */
int pages_printed = 0;
static int pplistmaxsize=0;

static unsigned char *pplist=0;	/* bitmap list for storing pages to print */

void
pagelist(char *list) {
	char c;
	int n, m;
	int state, start;

	if (list == 0) return;
	state = 1;
	start = 0;
	while ((c=*list) != '\0') {
		n = 0;
		while (isdigit(c)) {
			n = n * 10 + c - '0';
			c = *++list;
		}
		switch (state) {
		case 1:
			start = n;
		case 2:
			if (n/8+1 > pplistmaxsize) {
				pplistmaxsize = n/8+1;
				pplist = galloc(pplist, n/8+1, "page list");
			}
			for (m=start; m<=n; m++)
				pplist[m/8] |= 1<<(m%8);
			break;
		}
		switch (c) {
		case '-':
			state = 2;
			list++;
			break;
		case ',':
			state = 1;
			list++;
			break;
		case '\0':
			break;
		}
	}
}

BOOLEAN
pageon(void) {
	extern BOOLEAN debug;
	static BOOLEAN privdebug = FALSE;

	if (pplist == 0 && page_no != 0) {
		if (privdebug && !debug) {
			privdebug = FALSE;
			debug = TRUE;
		}
		return(TRUE);	/* no page list, print all pages */
	}
	if (page_no/8 < pplistmaxsize && (pplist[page_no/8] & 1<<(page_no%8))) {
		if (privdebug && !debug) {
			privdebug = FALSE;
			debug = TRUE;
		}
		return(TRUE);
	} else {
		if (!privdebug && debug) {
			privdebug = TRUE;
			debug = FALSE;
		}
		return(FALSE);
	}
}

static int stringhpos, stringvpos;

void
startstring(void) {
	if (!in_string) {
		stringhpos = hpos;
		stringvpos = vpos;
		if (pageon()) Bprint(Bstdout, "(");
		in_string = 1;
	}
}

void
endstring(void) {
	if (in_string) {
		if (pageon()) Bprint(Bstdout, ") %d %d w\n", stringhpos, stringvpos);
		in_string = 0;
	}
}

BOOLEAN
isinstring(void) {
	return(in_string);
}

void
startpage(void) {
	++char_no;
	++line_no;
	++page_no;
	if (pageon()) {
		++pages_printed;
		Bprint(Bstdout, "%s %d %d\n", PAGE, page_no, pages_printed);
		Bprint(Bstdout, "/saveobj save def\n");
		Bprint(Bstdout, "mark\n");
		Bprint(Bstdout, "%d pagesetup\n", pages_printed);
	}
}

void
endpage(void) {
	endstring();
	curpostfontid = -1;
	line_no = 0;
	char_no = 0;
	if (pageon()) {
		Bprint(Bstdout, "cleartomark\n");
		Bprint(Bstdout, "showpage\n");
		Bprint(Bstdout, "saveobj restore\n");
		Bprint(Bstdout, "%s %d %d\n", ENDPAGE, page_no, pages_printed);
	}
}

/* This was taken from postprint */

int
cat(char *filename) {
	Biobuf *bfile;
	Biobufhdr *Bfile;
	int n;
	static char buf[Bsize];

	if ((bfile = Bopen(filename, OREAD)) == 0) {
		return(1);
	}
	Bfile = &(bfile->Biobufhdr);
	while ((n=Bread(Bfile, buf, Bsize)) > 0) {
		if (Bwrite(Bstdout, buf, n) != n)
			break;
	}
	Bterm(Bfile);
	if (n != 0) {
		return(1);
	}
	return(0);
}
extern int debug;
void *
galloc(void *ptr, int size, char *perstr) {
	void *x;

	if ((x=realloc(ptr, size)) == 0) {
		perror(perstr);
		exits("malloc");
	}
	return(x);
}

static char *errorstrings[] = {
	{""},	/* NONE */
	{"WARNING"},
	{"FATAL"}
};

char *programname;
char *inputfilename = "<stdin>";
int inputlineno;

void
error(int errtype, char *fmt, ...) {
	va_list arg;

	Bflush(Bstdout);
	Bflush(Bstderr);
	fprint(2, "%s: %s:%d :%s: ", programname, inputfilename, inputlineno, errorstrings[errtype]);
	va_start(arg, fmt);
	vfprint(2, fmt, arg);
	va_end(arg);
	if (errtype == FATAL)
		exits("fatal error");
}