diff options
Diffstat (limited to 'mysys/my_symlink.c')
| -rw-r--r-- | mysys/my_symlink.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/mysys/my_symlink.c b/mysys/my_symlink.c new file mode 100644 index 00000000000..e195adcd4c5 --- /dev/null +++ b/mysys/my_symlink.c @@ -0,0 +1,171 @@ +/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA */ + +#include "mysys_priv.h" +#include "mysys_err.h" +#include <m_string.h> +#ifdef HAVE_REALPATH +#include <sys/param.h> +#include <sys/stat.h> +#endif + +/* + Reads the content of a symbolic link + If the file is not a symbolic link, return the original file name in to. +*/ + +int my_readlink(char *to, const char *filename, myf MyFlags) +{ +#ifndef HAVE_READLINK + strmov(to,filename); + return 0; +#else + int result=0; + int length; + DBUG_ENTER("my_readlink"); + + if ((length=readlink(filename, to, FN_REFLEN-1)) < 0) + { + /* Don't give an error if this wasn't a symlink */ + if ((my_errno=errno) == EINVAL) + { + strmov(to,filename); + } + else + { + if (MyFlags & MY_WME) + my_error(EE_CANT_READLINK, MYF(0), filename, errno); + result= -1; + } + } + else + to[length]=0; + DBUG_RETURN(result); +#endif /* HAVE_READLINK */ +} + + +/* Create a symbolic link */ + +int my_symlink(const char *content, const char *linkname, myf MyFlags) +{ +#ifndef HAVE_READLINK + return 0; +#else + int result; + DBUG_ENTER("my_symlink"); + + result= 0; + if (symlink(content, linkname)) + { + result= -1; + my_errno=errno; + if (MyFlags & MY_WME) + my_error(EE_CANT_SYMLINK, MYF(0), linkname, content, errno); + } + DBUG_RETURN(result); +#endif /* HAVE_READLINK */ +} + + +/* + Create a file and a symbolic link that points to this file + If linkname is a null pointer or equal to filename, we don't + create a link. + */ + + +File my_create_with_symlink(const char *linkname, const char *filename, + int createflags, int access_flags, myf MyFlags) +{ + File file; + int tmp_errno; + DBUG_ENTER("my_create_with_symlink"); + if ((file=my_create(filename, createflags, access_flags, MyFlags)) >= 0) + { + /* Test if we should create a link */ + if (linkname && strcmp(linkname,filename)) + { + /* Delete old link/file */ + if (MyFlags & MY_DELETE_OLD) + my_delete(linkname, MYF(0)); + /* Create link */ + if (my_symlink(filename, linkname, MyFlags)) + { + /* Fail, remove everything we have done */ + tmp_errno=my_errno; + my_close(file,MYF(0)); + my_delete(filename, MYF(0)); + file= -1; + my_errno=tmp_errno; + } + } + } + DBUG_RETURN(file); +} + + +/* + Resolve all symbolic links in path + 'to' may be equal to 'filename' + + Because purify gives a lot of UMR errors when using realpath(), + this code is disabled when using purify. + + If MY_RESOLVE_LINK is given, only do realpath if the file is a link. +*/ + +#if defined(SCO) +#define BUFF_LEN 4097 +#elif defined(MAXPATHLEN) +#define BUFF_LEN MAXPATHLEN +#else +#define BUFF_LEN FN_LEN +#endif + +int my_realpath(char *to, const char *filename, myf MyFlags) +{ +#if defined(HAVE_REALPATH) && !defined(HAVE_purify) && !defined(HAVE_BROKEN_REALPATH) + int result=0; + char buff[BUFF_LEN]; + struct stat stat_buff; + DBUG_ENTER("my_realpath"); + + if (!(MyFlags & MY_RESOLVE_LINK) || + (!lstat(filename,&stat_buff) && S_ISLNK(stat_buff.st_mode))) + { + char *ptr; + if ((ptr=realpath(filename,buff))) + strmake(to,ptr,FN_REFLEN-1); + else + { + /* Realpath didn't work; Use original name */ + my_errno=errno; + if (MyFlags & MY_WME) + my_error(EE_REALPATH, MYF(0), filename, my_errno); + if (to != filename) + strmov(to,filename); + result= -1; + } + } + return result; +#else + if (to != filename) + strmov(to,filename); + return 0; +#endif +} |