multi.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 "sam.h"

List	file = { 'p' };
ushort	tag;

File *
newfile(void)
{
	File *f;

	f = fileopen();
	inslist(&file, 0, f);
	f->tag = tag++;
	if(downloaded)
		outTs(Hnewname, f->tag);
	/* already sorted; file name is "" */
	return f;
}

int
whichmenu(File *f)
{
	int i;

	for(i=0; i<file.nused; i++)
		if(file.filepptr[i]==f)
			return i;
	return -1;
}

void
delfile(File *f)
{
	int w = whichmenu(f);

	if(w < 0)	/* e.g. x/./D */
		return;
	if(downloaded)
		outTs(Hdelname, f->tag);
	dellist(&file, w);
	fileclose(f);
}

void
fullname(String *name)
{
	if(name->n > 0 && name->s[0]!='/' && name->s[0]!=0)
		Strinsert(name, &curwd, (Posn)0);
}

void
fixname(String *name)
{
	String *t;
	char *s;

	fullname(name);
	s = Strtoc(name);
	if(strlen(s) > 0)
		s = cleanname(s);
	t = tmpcstr(s);
	Strduplstr(name, t);
	free(s);
	freetmpstr(t);

	if(Strispre(&curwd, name))
		Strdelete(name, 0, curwd.n);
}

void
sortname(File *f)
{
	int i, cmp, w;
	int dupwarned;

	w = whichmenu(f);
	dupwarned = FALSE;
	dellist(&file, w);
	if(f == cmd)
		i = 0;
	else{
		for(i=0; i<file.nused; i++){
			cmp = Strcmp(&f->name, &file.filepptr[i]->name);
			if(cmp==0 && !dupwarned){
				dupwarned = TRUE;
				warn_S(Wdupname, &f->name);
			}else if(cmp<0 && (i>0 || cmd==0))
				break;
		}
	}
	inslist(&file, i, f);
	if(downloaded)
		outTsS(Hmovname, f->tag, &f->name);
}

void
state(File *f, int cleandirty)
{
	if(f == cmd)
		return;
	f->unread = FALSE;
	if(downloaded && whichmenu(f)>=0){	/* else flist or menu */
		if(f->mod && cleandirty!=Dirty)
			outTs(Hclean, f->tag);
		else if(!f->mod && cleandirty==Dirty)
			outTs(Hdirty, f->tag);
	}
	if(cleandirty == Clean)
		f->mod = FALSE;
	else
		f->mod = TRUE;
}

File *
lookfile(String *s)
{
	int i;

	for(i=0; i<file.nused; i++)
		if(Strcmp(&file.filepptr[i]->name, s) == 0)
			return file.filepptr[i];
	return 0;
}