doio.c

早期freebsd实现

/* $RCSfile: doio.c,v $$Revision: 4.0.1.6 $$Date: 92/06/11 21:08:16 $
 *
 *    Copyright (c) 1991, Larry Wall
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 * $Log:	doio.c,v $
 * Revision 4.0.1.6  92/06/11  21:08:16  lwall
 * patch34: some systems don't declare h_errno extern in header files
 * 
 * Revision 4.0.1.5  92/06/08  13:00:21  lwall
 * patch20: some machines don't define ENOTSOCK in errno.h
 * patch20: new warnings for failed use of stat operators on filenames with \n
 * patch20: wait failed when STDOUT or STDERR reopened to a pipe
 * patch20: end of file latch not reset on reopen of STDIN
 * patch20: seek(HANDLE, 0, 1) went to eof because of ancient Ultrix workaround
 * patch20: fixed memory leak on system() for vfork() machines
 * patch20: get*by* routines now return something useful in a scalar context
 * patch20: h_errno now accessible via $?
 * 
 * Revision 4.0.1.4  91/11/05  16:51:43  lwall
 * patch11: prepared for ctype implementations that don't define isascii()
 * patch11: perl mistook some streams for sockets because they return mode 0 too
 * patch11: reopening STDIN, STDOUT and STDERR failed on some machines
 * patch11: certain perl errors should set EBADF so that $! looks better
 * patch11: truncate on a closed filehandle could dump
 * patch11: stats of _ forgot whether prior stat was actually lstat
 * patch11: -T returned true on NFS directory
 * 
 * Revision 4.0.1.3  91/06/10  01:21:19  lwall
 * patch10: read didn't work from character special files open for writing
 * patch10: close-on-exec wrongly set on system file descriptors
 * 
 * Revision 4.0.1.2  91/06/07  10:53:39  lwall
 * patch4: new copyright notice
 * patch4: system fd's are now treated specially
 * patch4: added $^F variable to specify maximum system fd, default 2
 * patch4: character special files now opened with bidirectional stdio buffers
 * patch4: taintchecks could improperly modify parent in vfork()
 * patch4: many, many itty-bitty portability fixes
 * 
 * Revision 4.0.1.1  91/04/11  17:41:06  lwall
 * patch1: hopefully straightened out some of the Xenix mess
 * 
 * Revision 4.0  91/03/20  01:07:06  lwall
 * 4.0 baseline.
 * 
 */

#include "EXTERN.h"
#include "perl.h"

#ifdef HAS_SOCKET
#include <sys/socket.h>
#include <netdb.h>
#ifndef ENOTSOCK
#include <net/errno.h>
#endif
#endif

#ifdef HAS_SELECT
#ifdef I_SYS_SELECT
#ifndef I_SYS_TIME
#include <sys/select.h>
#endif
#endif
#endif

#ifdef HOST_NOT_FOUND
extern int h_errno;
#endif

#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
#include <sys/ipc.h>
#ifdef HAS_MSG
#include <sys/msg.h>
#endif
#ifdef HAS_SEM
#include <sys/sem.h>
#endif
#ifdef HAS_SHM
#include <sys/shm.h>
#endif
#endif

#ifdef I_PWD
#include <pwd.h>
#endif
#ifdef I_GRP
#include <grp.h>
#endif
#ifdef I_UTIME
#include <utime.h>
#endif
#ifdef I_FCNTL
#include <fcntl.h>
#endif
#ifdef I_SYS_FILE
#include <sys/file.h>
#endif

int laststatval = -1;
int laststype = O_STAT;

static char* warn_nl = "Unsuccessful %s on filename containing newline";

bool
do_open(stab,name,len)
STAB *stab;
register char *name;
int len;
{
    FILE *fp;
    register STIO *stio = stab_io(stab);
    char *myname = savestr(name);
    int result;
    int fd;
    int writing = 0;
    char mode[3];		/* stdio file mode ("r\0" or "r+\0") */
    FILE *saveifp = Nullfp;
    FILE *saveofp = Nullfp;
    char savetype = ' ';

    mode[0] = mode[1] = mode[2] = '\0';
    name = myname;
    forkprocess = 1;		/* assume true if no fork */
    while (len && isSPACE(name[len-1]))
	name[--len] = '\0';
    if (!stio)
	stio = stab_io(stab) = stio_new();
    else if (stio->ifp) {
	fd = fileno(stio->ifp);
	if (stio->type == '-')
	    result = 0;
	else if (fd <= maxsysfd) {
	    saveifp = stio->ifp;
	    saveofp = stio->ofp;
	    savetype = stio->type;
	    result = 0;
	}
	else if (stio->type == '|')
	    result = mypclose(stio->ifp);
	else if (stio->ifp != stio->ofp) {
	    if (stio->ofp) {
		result = fclose(stio->ofp);
		fclose(stio->ifp);	/* clear stdio, fd already closed */
	    }
	    else
		result = fclose(stio->ifp);
	}
	else
	    result = fclose(stio->ifp);
	if (result == EOF && fd > maxsysfd)
	    fprintf(stderr,"Warning: unable to close filehandle %s properly.\n",
	      stab_ename(stab));
	stio->ofp = stio->ifp = Nullfp;
    }
    if (*name == '+' && len > 1 && name[len-1] != '|') {	/* scary */
	mode[1] = *name++;
	mode[2] = '\0';
	--len;
	writing = 1;
    }
    else  {
	mode[1] = '\0';
    }
    stio->type = *name;
    if (*name == '|') {
	/*SUPPRESS 530*/
	for (name++; isSPACE(*name); name++) ;
#ifdef TAINT
	taintenv();
	taintproper("Insecure dependency in piped open");
#endif
	fp = mypopen(name,"w");
	writing = 1;
    }
    else if (*name == '>') {
#ifdef TAINT
	taintproper("Insecure dependency in open");
#endif
	name++;
	if (*name == '>') {
	    mode[0] = stio->type = 'a';
	    name++;
	}
	else
	    mode[0] = 'w';
	writing = 1;
	if (*name == '&') {
	  duplicity:
	    name++;
	    while (isSPACE(*name))
		name++;
	    if (isDIGIT(*name))
		fd = atoi(name);
	    else {
		stab = stabent(name,FALSE);
		if (!stab || !stab_io(stab)) {
#ifdef EINVAL
		    errno = EINVAL;
#endif
		    goto say_false;
		}
		if (stab_io(stab) && stab_io(stab)->ifp) {
		    fd = fileno(stab_io(stab)->ifp);
		    if (stab_io(stab)->type == 's')
			stio->type = 's';
		}
		else
		    fd = -1;
	    }
	    if (!(fp = fdopen(fd = dup(fd),mode))) {
		close(fd);
	    }
	}
	else {
	    while (isSPACE(*name))
		name++;
	    if (strEQ(name,"-")) {
		fp = stdout;
		stio->type = '-';
	    }
	    else  {
		fp = fopen(name,mode);
	    }
	}
    }
    else {
	if (*name == '<') {
	    mode[0] = 'r';
	    name++;
	    while (isSPACE(*name))
		name++;
	    if (*name == '&')
		goto duplicity;
	    if (strEQ(name,"-")) {
		fp = stdin;
		stio->type = '-';
	    }
	    else
		fp = fopen(name,mode);
	}
	else if (name[len-1] == '|') {
#ifdef TAINT
	    taintenv();
	    taintproper("Insecure dependency in piped open");
#endif
	    name[--len] = '\0';
	    while (len && isSPACE(name[len-1]))
		name[--len] = '\0';
	    /*SUPPRESS 530*/
	    for (; isSPACE(*name); name++) ;
	    fp = mypopen(name,"r");
	    stio->type = '|';
	}
	else {
	    stio->type = '<';
	    /*SUPPRESS 530*/
	    for (; isSPACE(*name); name++) ;
	    if (strEQ(name,"-")) {
		fp = stdin;
		stio->type = '-';
	    }
	    else
		fp = fopen(name,"r");
	}
    }
    if (!fp) {
	if (dowarn && stio->type == '<' && index(name, '\n'))
	    warn(warn_nl, "open");
	Safefree(myname);
	goto say_false;
    }
    Safefree(myname);
    if (stio->type &&
      stio->type != '|' && stio->type != '-') {
	if (fstat(fileno(fp),&statbuf) < 0) {
	    (void)fclose(fp);
	    goto say_false;
	}
	if (S_ISSOCK(statbuf.st_mode))
	    stio->type = 's';	/* in case a socket was passed in to us */
#ifdef HAS_SOCKET
	else if (
#ifdef S_IFMT
	    !(statbuf.st_mode & S_IFMT)
#else
	    !statbuf.st_mode
#endif
	) {
	    int buflen = sizeof tokenbuf;
	    if (getsockname(fileno(fp), tokenbuf, &buflen) >= 0
		|| errno != ENOTSOCK)
		stio->type = 's'; /* some OS's return 0 on fstat()ed socket */
				/* but some return 0 for streams too, sigh */
	}
#endif
    }
    if (saveifp) {		/* must use old fp? */
	fd = fileno(saveifp);
	if (saveofp) {
	    fflush(saveofp);		/* emulate fclose() */
	    if (saveofp != saveifp) {	/* was a socket? */
		fclose(saveofp);
		if (fd > 2)
		    Safefree(saveofp);
	    }
	}
	if (fd != fileno(fp)) {
	    int pid;
	    STR *str;

	    dup2(fileno(fp), fd);
	    str = afetch(fdpid,fileno(fp),TRUE);
	    pid = str->str_u.str_useful;
	    str->str_u.str_useful = 0;
	    str = afetch(fdpid,fd,TRUE);
	    str->str_u.str_useful = pid;
	    fclose(fp);

	}
	fp = saveifp;
	clearerr(fp);
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fd = fileno(fp);
    fcntl(fd,F_SETFD,fd > maxsysfd);
#endif
    stio->ifp = fp;
    if (writing) {
	if (stio->type == 's'
	  || (stio->type == '>' && S_ISCHR(statbuf.st_mode)) ) {
	    if (!(stio->ofp = fdopen(fileno(fp),"w"))) {
		fclose(fp);
		stio->ifp = Nullfp;
		goto say_false;
	    }
	}
	else
	    stio->ofp = fp;
    }
    return TRUE;

say_false:
    stio->ifp = saveifp;
    stio->ofp = saveofp;
    stio->type = savetype;
    return FALSE;
}

FILE *
nextargv(stab)
register STAB *stab;
{
    register STR *str;
#ifndef FLEXFILENAMES
    int filedev;
    int fileino;
#endif
    int fileuid;
    int filegid;
    static int filemode = 0;
    static int lastfd;
    static char *oldname;

    if (!argvoutstab)
	argvoutstab = stabent("ARGVOUT",TRUE);
    if (filemode & (S_ISUID|S_ISGID)) {
	fflush(stab_io(argvoutstab)->ifp);  /* chmod must follow last write */
#ifdef HAS_FCHMOD
	(void)fchmod(lastfd,filemode);
#else
	(void)chmod(oldname,filemode);
#endif
    }
    filemode = 0;
    while (alen(stab_xarray(stab)) >= 0) {
	str = ashift(stab_xarray(stab));
	str_sset(stab_val(stab),str);
	STABSET(stab_val(stab));
	oldname = str_get(stab_val(stab));
	if (do_open(stab,oldname,stab_val(stab)->str_cur)) {
	    if (inplace) {
#ifdef TAINT
		taintproper("Insecure dependency in inplace open");
#endif
		if (strEQ(oldname,"-")) {
		    str_free(str);
		    defoutstab = stabent("STDOUT",TRUE);
		    return stab_io(stab)->ifp;
		}
#ifndef FLEXFILENAMES
		filedev = statbuf.st_dev;
		fileino = statbuf.st_ino;
#endif
		filemode = statbuf.st_mode;
		fileuid = statbuf.st_uid;
		filegid = statbuf.st_gid;
		if (!S_ISREG(filemode)) {
		    warn("Can't do inplace edit: %s is not a regular file",
		      oldname );
		    do_close(stab,FALSE);
		    str_free(str);
		    continue;
		}
		if (*inplace) {
#ifdef SUFFIX
		    add_suffix(str,inplace);
#else
		    str_cat(str,inplace);
#endif
#ifndef FLEXFILENAMES
		    if (stat(str->str_ptr,&statbuf) >= 0
		      && statbuf.st_dev == filedev
		      && statbuf.st_ino == fileino ) {
			warn("Can't do inplace edit: %s > 14 characters",
			  str->str_ptr );
			do_close(stab,FALSE);
			str_free(str);
			continue;
		    }
#endif
#ifdef HAS_RENAME
#ifndef DOSISH
		    if (rename(oldname,str->str_ptr) < 0) {
			warn("Can't rename %s to %s: %s, skipping file",
			  oldname, str->str_ptr, strerror(errno) );
			do_close(stab,FALSE);
			str_free(str);
			continue;
		    }
#else
		    do_close(stab,FALSE);
		    (void)unlink(str->str_ptr);
		    (void)rename(oldname,str->str_ptr);
		    do_open(stab,str->str_ptr,stab_val(stab)->str_cur);
#endif /* MSDOS */
#else
		    (void)UNLINK(str->str_ptr);
		    if (link(oldname,str->str_ptr) < 0) {
			warn("Can't rename %s to %s: %s, skipping file",
			  oldname, str->str_ptr, strerror(errno) );
			do_close(stab,FALSE);
			str_free(str);
			continue;
		    }
		    (void)UNLINK(oldname);
#endif
		}
		else {
#ifndef DOSISH
		    if (UNLINK(oldname) < 0) {
			warn("Can't rename %s to %s: %s, skipping file",
			  oldname, str->str_ptr, strerror(errno) );
			do_close(stab,FALSE);
			str_free(str);
			continue;
		    }
#else
		    fatal("Can't do inplace edit without backup");
#endif
		}

		str_nset(str,">",1);
		str_cat(str,oldname);
		errno = 0;		/* in case sprintf set errno */
		if (!do_open(argvoutstab,str->str_ptr,str->str_cur)) {
		    warn("Can't do inplace edit on %s: %s",
		      oldname, strerror(errno) );
		    do_close(stab,FALSE);
		    str_free(str);
		    continue;
		}
		defoutstab = argvoutstab;
		lastfd = fileno(stab_io(argvoutstab)->ifp);
		(void)fstat(lastfd,&statbuf);
#ifdef HAS_FCHMOD
		(void)fchmod(lastfd,filemode);
#else
		(void)chmod(oldname,filemode);
#endif
		if (fileuid != statbuf.st_uid || filegid != statbuf.st_gid) {
#ifdef HAS_FCHOWN
		    (void)fchown(lastfd,fileuid,filegid);
#else
#ifdef HAS_CHOWN
		    (void)chown(oldname,fileuid,filegid);
#endif
#endif
		}
	    }
	    str_free(str);
	    return stab_io(stab)->ifp;
	}
	else
	    fprintf(stderr,"Can't open %s: %s\n",str_get(str), strerror(errno));
	str_free(str);
    }
    if (inplace) {
	(void)do_close(argvoutstab,FALSE);
	defoutstab = stabent("STDOUT",TRUE);
    }
    return Nullfp;
}

#ifdef HAS_PIPE
void
do_pipe(str, rstab, wstab)
STR *str;
STAB *rstab;
STAB *wstab;
{
    register STIO *rstio;
    register STIO *wstio;
    int fd[2];

    if (!rstab)
	goto badexit;
    if (!wstab)
	goto badexit;

    rstio = stab_io(rstab);
    wstio = stab_io(wstab);

    if (!rstio)
	rstio = stab_io(rstab) = stio_new();
    else if (rstio->ifp)
	do_close(rstab,FALSE);
    if (!wstio)
	wstio = stab_io(wstab) = stio_new();
    else if (wstio->ifp)
	do_close(wstab,FALSE);

    if (pipe(fd) < 0)
	goto badexit;
    rstio->ifp = fdopen(fd[0], "r");
    wstio->ofp = fdopen(fd[1], "w");
    wstio->ifp = wstio->ofp;
    rstio->type = '<';
    wstio->type = '>';
    if (!rstio->ifp || !wstio->ofp) {
	if (rstio->ifp) fclose(rstio->ifp);
	else close(fd[0]);
	if (wstio->ofp) fclose(wstio->ofp);
	else close(fd[1]);
	goto badexit;
    }

    str_sset(str,&str_yes);
    return;

badexit:
    str_sset(str,&str_undef);
    return;
}
#endif

bool
do_close(stab,explicit)
STAB *stab;
bool explicit;
{
    bool retval = FALSE;
    register STIO *stio;
    int status;

    if (!stab)
	stab = argvstab;
    if (!stab) {
	errno = EBADF;
	return FALSE;
    }
    stio = stab_io(stab);
    if (!stio) {		/* never opened */
	if (dowarn && explicit)
	    warn("Close on unopened file <%s>",stab_ename(stab));
	return FALSE;
    }
    if (stio->ifp) {
	if (stio->type == '|') {
	    status = mypclose(stio->ifp);
	    retval = (status == 0);
	    statusvalue = (unsigned short)status & 0xffff;
	}
	else if (stio->type == '-')
	    retval = TRUE;
	else {