{"id":3547,"date":"2017-08-19T08:31:52","date_gmt":"2017-08-19T00:31:52","guid":{"rendered":"https:\/\/ixyzero.com\/blog\/?p=3547"},"modified":"2017-08-19T08:31:52","modified_gmt":"2017-08-19T00:31:52","slug":"linux%e4%b8%8b%e7%94%a8c%e8%af%ad%e8%a8%80%e5%ae%9e%e7%8e%b0lsattrchattr%e5%91%bd%e4%bb%a4%e7%9a%84%e5%8a%9f%e8%83%bd","status":"publish","type":"post","link":"https:\/\/ixyzero.com\/blog\/archives\/3547.html","title":{"rendered":"Linux\u4e0b\u7528C\u8bed\u8a00\u5b9e\u73b0lsattr\/chattr\u547d\u4ee4\u7684\u529f\u80fd"},"content":{"rendered":"

=Start=<\/p>\n

\u7f18\u7531\uff1a<\/h4>\n

\u5b66\u4e60\u3001\u63d0\u9ad8\u9700\u8981<\/p>\n

\u6b63\u6587\uff1a<\/h4>\n

\u53c2\u8003\u89e3\u7b54\uff1a<\/h5>\n

\u4e4b\u524d\u5bf9ioctl()\u51fd\u6570\u4e0d\u719f\uff0c\u5bfc\u81f4\u5728\u7528\u5b83\u5b9e\u73b0lsattr\/chattr\u547d\u4ee4\u7684\u8fc7\u7a0b\u4e2d\u8e29\u4e86\u51e0\u4e2a\u5751\uff0c\u5dee\u70b9\u8981\u653e\u5f03\u4e86\uff0c\u8fd8\u597d\u540e\u6765\u6709\u4e00\u4e2a\u6210\u529f\u7684\u4f8b\u5b50\u53ef\u4ee5\u53c2\u8003\uff0c\u4ee5\u4fbf\u5bf9\u6bd4\u4e24\u8005\u4e4b\u95f4\u7684\u4e0d\u540c\u4e4b\u5904\uff0c\u4ece\u800c\u627e\u6253\u95ee\u9898\u6240\u5728\u3002\u5148\u7ed9\u51fa\u4fee\u6539\u540e\u53ef\u4ee5\u7528\u7684\u7248\u672c\uff1a<\/p>\n

\n
\n
\n
\n\n\n\n
\n
\n
\/* setflags.c - set the ext2 attributes for a set of files *\/<\/code><\/div>\n
<\/div>\n
\/* The first parameter to this program is a string consisting of<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>0 (an empty string is okay) or more of the letters I, A, S, and<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>N. This string specifies which ext2 attributes should be turned<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>on for the files which are specified on the rest of the command<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>line -- the rest of the attributes are turned off. The letters<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>stand for immutable, append-only, sync, and nodump, respectively.<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0<\/code>For example, the command \"setflags IN file1 file2\" turns on the<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>immutable and nodump flags for files file1 and file2, but turns<\/code><\/div>\n
\u00a0\u00a0\u00a0<\/code>off the sync and append-only flags for those files. *\/<\/code><\/div>\n
<\/div>\n
#include <errno.h><\/code><\/div>\n
#include <fcntl.h><\/code><\/div>\n
#include <linux\/ext2_fs.h><\/code><\/div>\n
#include <stdio.h><\/code><\/div>\n
#include <string.h><\/code><\/div>\n
#include <sys\/ioctl.h><\/code><\/div>\n
#include <unistd.h><\/code><\/div>\n
<\/div>\n
int<\/code>\u00a0main(<\/code>int<\/code>\u00a0argc,\u00a0<\/code>char<\/code>\u00a0** argv) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>char<\/code>\u00a0** filename = argv +\u00a0<\/code>1<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0fd;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>int<\/code>\u00a0old_flags =\u00a0<\/code>0<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>\/* make sure the flags to set were specified, along with<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>some file names *\/<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(argc <\u00a0<\/code>3<\/code>) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>fprintf(stderr,\u00a0<\/code>\"setflags usage: [I][A][S][N] <filenames>\\n\"<\/code>);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a01<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"FS_IMMUTABLE_FL = 0x%08x, %d\\n\"<\/code>, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"FS_APPEND_FL = 0x%08x, %d\\n\"<\/code>, FS_APPEND_FL, FS_APPEND_FL);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"FS_SYNC_FL = 0x%08x, %d\\n\"<\/code>, FS_SYNC_FL, FS_SYNC_FL);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"FS_NODUMP_FL = 0x%08x, %d\\n\"<\/code>, FS_NODUMP_FL, FS_NODUMP_FL);<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>\/* iterate over all of the file names in argv[] *\/<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>while<\/code>\u00a0(*(++filename)) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/* Unlike normal attributes, ext2 attributes can only<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>be set if we have a file descriptor (a file name isn't sufficient).<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>We don't need write access to set the ext2 attributes, so O_RDONLY is fine. *\/<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>fd = open(*filename, O_RDONLY);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(fd <\u00a0<\/code>0<\/code>) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>fprintf(stderr,\u00a0<\/code>\"cannot open %s: %s\\n\"<\/code>, *filename, strerror(errno));<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>continue<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/* Sets the attributes as specified by the contents of flags. *\/<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(ioctl(fd, FS_IOC_GETFLAGS, &old_flags) == -<\/code>1<\/code>) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>fprintf(stderr,\u00a0<\/code>\"ioctl failed on %s: %s\\n\"<\/code>, *filename, strerror(errno));<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>close(fd);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>continue<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}\u00a0<\/code>else<\/code>\u00a0{<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"current attrs: 0x%08x\\n\"<\/code>, old_flags);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/ old_flags |= FS_IMMUTABLE_FL;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/\/ printf(\"\\nold_flags |= FS_IMMUTABLE_FL >>> old_flags = 0x%08x\\n\", old_flags);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(strchr(argv[<\/code>1<\/code>],\u00a0<\/code>'I'<\/code>)) old_flags |= FS_IMMUTABLE_FL;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(strchr(argv[<\/code>1<\/code>],\u00a0<\/code>'A'<\/code>)) old_flags |= FS_APPEND_FL;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(strchr(argv[<\/code>1<\/code>],\u00a0<\/code>'S'<\/code>)) old_flags |= FS_SYNC_FL;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(strchr(argv[<\/code>1<\/code>],\u00a0<\/code>'N'<\/code>)) old_flags |= FS_NODUMP_FL;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>printf(<\/code>\"\\nold_flags = 0x%08x\\n\"<\/code>, old_flags);<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>\/* Sets the attributes as specified by the contents of flags. *\/<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>if<\/code>\u00a0(ioctl(fd, FS_IOC_SETFLAGS, &old_flags) == -<\/code>1<\/code>) {<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>fprintf(stderr,\u00a0<\/code>\"ioctl failed on %s: %s\\n\"<\/code>, *filename, strerror(errno));<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>close(fd);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>continue<\/code>;<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code>close(fd);<\/code><\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>}<\/code><\/div>\n
<\/div>\n
\u00a0\u00a0\u00a0\u00a0<\/code>return<\/code>\u00a00<\/code>;<\/code><\/div>\n
}<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

\u7136\u540e\u518d\u8bf4\u4e00\u4e0b\u5728\u4fee\u6539\u8fc7\u7a0b\u4e2d\u78b0\u5230\u7684\u95ee\u9898\uff1a<\/p>\n

\u95ee\u9898\u4e00\u3001\u65e0\u6cd5\u7f16\u8bd1\u6210\u529f\uff0c\u62a5\u9519\u5982\u4e0b\uff1a<\/h6>\n

\/usr\/include\/linux\/ext2_fs.h: In function \u2018ext2_mask_flags\u2019:
\n\/usr\/include\/linux\/ext2_fs.h:182: error: \u2018FS_DIRSYNC_FL\u2019 undeclared (first use in this function)
\n\/usr\/include\/linux\/ext2_fs.h:182: error: (Each undeclared identifier is reported only once
\n\/usr\/include\/linux\/ext2_fs.h:182: error: for each function it appears in.)
\n\/usr\/include\/linux\/ext2_fs.h:182: error: \u2018FS_TOPDIR_FL\u2019 undeclared (first use in this function)
\n\/usr\/include\/linux\/ext2_fs.h:184: error: \u2018FS_NODUMP_FL\u2019 undeclared (first use in this function)
\n\/usr\/include\/linux\/ext2_fs.h:184: error: \u2018FS_NOATIME_FL\u2019 undeclared (first use in this function)<\/p><\/blockquote>\n

\u539f\u56e0\uff1a<\/p>\n

\u9700\u8981\u5728\u300c#include <linux\/ext2_fs.h>\u300d\u4e4b\u524d\u5148\u5f15\u5165\u300c#include <linux\/fs.h>\u300d\uff0c\u6709\u4e00\u4e2a\u987a\u5e8f\u5173\u7cfb\uff01<\/p>\n

\u95ee\u9898\u4e8c\uff1a\u6267\u884c\u300cioctl(fd, FS_IOC_SETFLAGS, &flags)\u300d\u65f6\u62a5\u9519\u300cOperation not supported\u300d<\/span><\/h6>\n
\n
\n
\n
\n\n\n\n
\n
\n
current flags:\u00a0<\/code>0x00080000<\/code><\/div>\n
desire flags =\u00a0<\/code>0x00080010<\/code><\/div>\n
ioctl(flags) =\u00a0<\/code>0x00000010<\/code><\/div>\n
ioctl failed on filename: Operation not supported<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

\u539f\u56e0\uff1a<\/p>\n

\u5728\u8bed\u53e5\u300cioctl(fd, FS_IOC_SETFLAGS, &flags)\u300d\u91cc\u9762\u4f7f\u7528\u7684flags\u53d8\u91cf\u7684\u503c\u4e0d\u80fd\u662f0\u548cFS_IMMUTABLE_FL\u7b49\u53d8\u91cf\u7684\u5f02\u6216\u503c\uff0cflags\u7684\u521d\u59cb\u503c\u6700\u597d\u4e3a\u6587\u4ef6\u539f\u5148\u7684\u5c5e\u6027\u503c\uff08\u4e00\u822c\u4e3a524288\uff0c\u5341\u516d\u8fdb\u5236\u8868\u793a\u4e3a0x00080000\uff09\uff0c\u518d\u548c\u9700\u8981\u8bbe\u7f6e\u7684FS_IMMUTABLE_FL\u7b49\u53d8\u91cf\u8fdb\u884c\u5f02\u6216\uff0c\u7136\u540e\u4f5c\u4e3aioctl\u7684\u53c2\u6570\u624d\u4e0d\u4f1a\u62a5\u9519\u3002<\/p>\n

\u6240\u4ee5\uff0c\u63a8\u8350\u7684\u89e3\u51b3\u529e\u6cd5\u5c31\u662f\u5148\u300cioctl(fd,\u00a0FS_IOC_GETFLAGS, &old_flags)\u300d\uff0c\u7136\u540e\u5bf9old_flags\u8fdb\u884c\u5f02\u6216\uff0c\u6700\u540e\u6267\u884c\u300cioctl(fd, FS_IOC_SETFLAGS, &old_flags)\u300d\u3002<\/p>\n

\u53c2\u8003\u94fe\u63a5\uff1a<\/h5>\n

#\u51fd\u6570\u624b\u518c
\nhttp:\/\/man7.org\/linux\/man-pages\/man2\/ioctl.2.html<\/a>
\nhttp:\/\/man7.org\/linux\/man-pages\/man2\/ioctl_iflags.2.html<\/a><\/p>\n

#\u9519\u8bef\u7248\u672c\uff08\u53ea\u5dee\u4e00\u70b9\u70b9\uff09
\nhttps:\/\/stackoverflow.com\/questions\/16961592\/performing-the-equivalent-of-chattr-i-filename-txt-from-linux-application<\/a>
\nhttp:\/\/www.danlj.org\/lad\/src\/setflags.c.html<\/a>
\nhttps:\/\/stackoverflow.com\/questions\/32488017\/how-do-i-chattr-i-an-open-file-descriptor-in-c<\/a><\/p>\n

#\u6210\u529f\u7248\u672c\uff08\u5199\u5f97\u592a\u590d\u6742\u4e86\uff09
\nhttps:\/\/github.com\/posborne\/linux-programming-interface-exercises\/blob\/master\/15-file-attributes\/chattr.c<\/a><\/p>\n

#FS_DIRSYNC_FL\u7b49\u53d8\u91cf\u672a\u5b9a\u4e49\u9519\u8bef
\nhttps:\/\/stackoverflow.com\/questions\/6969303\/whats-wrong-with-linux-ext2-fs-h<\/a>
\nhttps:\/\/ubuntuforums.org\/showthread.php?t=1408802<\/a>
\nhttp:\/\/forum.ubuntu.org.cn\/viewtopic.php?f=77&t=319496<\/a><\/p>\n

=END=<\/p>\n","protected":false},"excerpt":{"rendered":"

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