tmp.c

操作系统源代码

/* tmp.c */

/* Author:
 *	Steve Kirkendall
 *	14407 SW Teal Blvd. #C
 *	Beaverton, OR 97005
 *	[e-mail]
 */


/* This file contains functions which create & readback a TMPFILE */


#include "config.h"
#include "vi.h"
#if TOS
# include <stat.h>
#else
# if OSK
#  include "osk.h"
# else
#  if AMIGA
#   include "amistat.h"
#  else
#   include <sys/stat.h>
#  endif
# endif
#endif
#if TURBOC
# include <process.h>
#endif

#ifndef NO_MODELINES
static void do_modelines(l, stop)
	long	l;	/* line number to start at */
	long	stop;	/* line number to stop at */
{
	char	*str;	/* used to scan through the line */
	char	*start;	/* points to the start of the line */
	char	buf[80];

	/* if modelines are disabled, then do nothing */
	if (!*o_modelines)
	{
		return;
	}

	/* for each line... */
	for (; l <= stop; l++)
	{
		/* for each position in the line.. */
		for (str = fetchline(l); *str; str++)
		{
			/* if it is the start of a modeline command... */
			if ((str[0] == 'e' && str[1] == 'x'
			  || str[0] == 'v' && str[1] == 'i')
			  && str[2] == ':')
			{
				start = str += 3;

				/* find the end */
				for (str = start + strlen(start); *--str != ':'; )
				{
				}

				/* if it is a well-formed modeline, execute it */
				if (str > start && str - start < sizeof buf)
				{
					strncpy(buf, start, (int)(str - start));
					exstring(buf, str - start, '\\');
					break;
				}
			}
		}
	}
}
#endif


/* The FAIL() macro prints an error message and then exits. */
#define FAIL(why,arg)	mode = MODE_EX; msg(why, arg); endwin(); exit(9)

/* This is the name of the temp file */
static char	tmpname[80];

/* This function creates the temp file and copies the original file into it.
 * Returns if successful, or stops execution if it fails.
 */
int tmpstart(filename)
	char		*filename; /* name of the original file */
{
	int		origfd;	/* fd used for reading the original file */
	struct stat	statb;	/* stat buffer, used to examine inode */
	REG BLK		*this;	/* pointer to the current block buffer */
	REG BLK		*next;	/* pointer to the next block buffer */
	int		inbuf;	/* number of characters in a buffer */
	int		nread;	/* number of bytes read */
	REG int		j, k;
	int		i;
	long		nbytes;

	/* switching to a different file certainly counts as a change */
	changes++;
	redraw(MARK_UNSET, FALSE);

	/* open the original file for reading */
	*origname = '\0';
	if (filename && *filename)
	{
		strcpy(origname, filename);
		origfd = open(origname, O_RDONLY);
		if (origfd < 0 && errno != ENOENT)
		{
			msg("Can't open \"%s\"", origname);
			return tmpstart("");
		}
		if (origfd >= 0)
		{
			if (stat(origname, &statb) < 0)
			{
				FAIL("Can't stat \"%s\"", origname);
			}
#if TOS
			if (origfd >= 0 && (statb.st_mode & S_IJDIR))
#else
# if OSK
			if (origfd >= 0 && (statb.st_mode & S_IFDIR))
# else
			if (origfd >= 0 && (statb.st_mode & S_IFMT) != S_IFREG)
# endif
#endif
			{
				msg("\"%s\" is not a regular file", origname);
				return tmpstart("");
			}
		}
		else
		{
			stat(".", &statb);
		}
		if (origfd >= 0)
		{
			origtime = statb.st_mtime;
#if OSK
			if (*o_readonly || !(statb.st_mode &
				  ((getuid() >> 16) == 0 ? S_IOWRITE | S_IWRITE :
				  ((statb.st_gid != (getuid() >> 16) ? S_IOWRITE : S_IWRITE)))))
#endif
#if AMIGA || MSDOS || (TOS && defined(__GNUC__))
			if (*o_readonly || !(statb.st_mode & S_IWRITE))
#endif
#if TOS && !defined(__GNUC__)
			if (*o_readonly || (statb.st_mode & S_IJRON))
#endif
#if ANY_UNIX
			if (*o_readonly || !(statb.st_mode &
				  ((geteuid() == 0) ? 0222 :
				  ((statb.st_uid != geteuid() ? 0022 : 0200)))))
#endif
#if VMS
			if (*o_readonly)
#endif
			{
				setflag(file, READONLY);
			}
		}
		else
		{
			origtime = 0L;
		}
	}
	else
	{
		setflag(file, NOFILE);
		origfd = -1;
		origtime = 0L;
		stat(".", &statb);
	}

	/* make a name for the tmp file */
	tmpnum++;
#if MSDOS || TOS
	/* MS-Dos doesn't allow multiple slashes, but supports drives
	 * with current directories.
	 * This relies on TMPNAME beginning with "%s\\"!!!!
	 */
	strcpy(tmpname, o_directory);
	if ((i = strlen(tmpname)) && !strchr(":/\\", tmpname[i-1]))
		tmpname[i++]=SLASH;
	sprintf(tmpname+i, TMPNAME+3, getpid(), tmpnum);
#else
	sprintf(tmpname, TMPNAME, o_directory, getpid(), tmpnum);
#endif

	/* make sure nobody else is editing the same file */
	if (access(tmpname, 0) == 0)
	{
		FAIL("Temp file \"%s\" already exists?", tmpname);
	}

	/* create the temp file */
#if ANY_UNIX
	close(creat(tmpname, 0600));		/* only we can read it */
#else
	close(creat(tmpname, FILEPERMS));	/* anybody body can read it, alas */
#endif
	tmpfd = open(tmpname, O_RDWR | O_BINARY);
	if (tmpfd < 0)
	{
		FAIL("Can't create temp file... Does directory \"%s\" exist?", o_directory);
		return 1;
	}

	/* allocate space for the header in the file */
	write(tmpfd, hdr.c, (unsigned)BLKSIZE);
	write(tmpfd, tmpblk.c, (unsigned)BLKSIZE);

#ifndef NO_RECYCLE
	/* initialize the block allocator */
	/* This must already be done here, before the first attempt
	 * to write to the new file! GB */
	garbage();
#endif

	/* initialize lnum[] */
	for (i = 1; i < MAXBLKS; i++)
	{
		lnum[i] = INFINITY;
	}
	lnum[0] = 0;

	/* if there is no original file, then create a 1-line file */
	if (origfd < 0)
	{
		hdr.n[0] = 0;	/* invalid inode# denotes new file */

		this = blkget(1); 	/* get the new text block */
		strcpy(this->c, "\n");	/* put a line in it */

		lnum[1] = 1L;	/* block 1 ends with line 1 */
		nlines = 1L;	/* there is 1 line in the file */
		nbytes = 1L;

		if (*origname)
		{
			msg("\"%s\" [NEW FILE]  1 line, 1 char", origname);
		}
		else
		{
			msg("\"[NO FILE]\"  1 line, 1 char");
		}
	}
	else /* there is an original file -- read it in */
	{
		nbytes = nlines = 0;

		/* preallocate 1 "next" buffer */
		i = 1;
		next = blkget(i);
		inbuf = 0;

		/* loop, moving blocks from orig to tmp */
		for (;;)
		{
			/* "next" buffer becomes "this" buffer */
			this = next;

			/* read [more] text into this block */
			nread = tread(origfd, &this->c[inbuf], BLKSIZE - 1 - inbuf);
			if (nread < 0)
			{
				close(origfd);
				close(tmpfd);
				tmpfd = -1;
				unlink(tmpname);
				FAIL("Error reading \"%s\"", origname);
			}

			/* convert NUL characters to something else */
			for (j = k = inbuf; k < inbuf + nread; k++)
			{
				if (!this->c[k])
				{
					setflag(file, HADNUL);
					this->c[j++] = 0x80;
				}
#ifndef CRUNCH
				else if (*o_beautify && this->c[k] < ' ' && this->c[k] > 0)
				{
					if (this->c[k] == '\t'
					 || this->c[k] == '\n'
					 || this->c[k] == '\f')
					{
						this->c[j++] = this->c[k];
					}
					else if (this->c[k] == '\b')
					{
						/* delete '\b', but complain */
						setflag(file, HADBS);
					}
					/* else silently delete control char */
				}
#endif
				else
				{
					this->c[j++] = this->c[k];
				}
			}
			inbuf = j;

			/* if the buffer is empty, quit */
			if (inbuf == 0)
			{
				goto FoundEOF;
			}

#if MSDOS || TOS
/* BAH! MS text mode read fills inbuf, then compresses eliminating \r
   but leaving garbage at end of buf. The same is true for TURBOC. GB. */

			memset(this->c + inbuf, '\0', BLKSIZE - inbuf);
#endif

			/* search backward for last newline */
			for (k = inbuf; --k >= 0 && this->c[k] != '\n';)
			{
			}
			if (k++ < 0)
			{
				if (inbuf >= BLKSIZE - 1)
				{
					k = 80;
				}
				else
				{
					k = inbuf;
				}
			}

			/* allocate next buffer */
			next = blkget(++i);

			/* move fragmentary last line to next buffer */
			inbuf -= k;
			for (j = 0; k < BLKSIZE; j++, k++)
			{
				next->c[j] = this->c[k];
				this->c[k] = 0;
			}

			/* if necessary, add a newline to this buf */
			for (k = BLKSIZE - inbuf; --k >= 0 && !this->c[k]; )
			{
			}
			if (this->c[k] != '\n')
			{
				setflag(file, ADDEDNL);
				this->c[k + 1] = '\n';
			}

			/* count the lines in this block */
			for (k = 0; k < BLKSIZE && this->c[k]; k++)
			{
				if (this->c[k] == '\n')
				{
					nlines++;
				}
				nbytes++;
			}
			lnum[i - 1] = nlines;
		}
FoundEOF:

		/* if this is a zero-length file, add 1 line */
		if (nlines == 0)
		{
			this = blkget(1); 	/* get the new text block */
			strcpy(this->c, "\n");	/* put a line in it */

			lnum[1] = 1;	/* block 1 ends with line 1 */