The Linux Programming Interface

File Attributes 297 15.4.2 Permissions on Directories...................................................................... Dire ...

298 Chapter 15 The rules applied by the kernel when checking permissions are as follows: If the process is privileged, all acce ...

File Attributes 299 other UNIX implementations, a privileged process can execute a file even when no permission category grants ...

300 Chapter 15 The problem is that if the pathname given to access() is a symbolic link, and a malicious user manages to change ...

File Attributes 301 A file’s sticky permission bit is set via the chmod command (chmod +t file) or via the chmod() system call. ...

302 Chapter 15 Listing 15-5 illustrates the use of umask() in conjunction with open() and mkdir(). When we run this program, we ...

File Attributes 303 if (stat(MYDIR, &sb) == -1) errExit("stat-%s", MYDIR); printf("Requested dir. perms: %s\n", filePermStr( ...

304 Chapter 15 In order to modify selected bits of the file permissions, we first retrieve the existing permissions using stat() ...

File Attributes 305 The first Linux file system to support i-node flags was ext2, and these flags are some- times referred to as ...

306 Chapter 15 The various FL_* flags and their meanings are as follows: FS_APPEND_FL The file can be opened for writing only if ...

File Attributes 307 FS_NODUMP_FL Don’t include this file in backups made using dump(8). The effect of this flag is dependent on ...

308 Chapter 15 Within a program, i-node flags can be retrieved and modified using the ioctl() FS_IOC_GETFLAGS and FS_IOC_SETFLAG ...

File Attributes 309 15.7 Exercises 15-1. Section 15.4 contained several statements about the permissions required for various fi ...

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Chapter 16: Extended Attributes This chapter describes extended attributes (EAs), which allow arbitrary metadata, in the form of ...

312 Chapter 16 EA namespaces EAs have names of the form namespace.name. The namespace component serves to separate EAs into func ...

Extended Attributes 313 user.x="The past is not dead." user.y="In fact, it's not even past." $ setfattr -n user.x tfile Change v ...

314 Chapter 16 This prevents arbitrary users from attaching EAs to directories such as /tmp, which are publicly writable (and so ...

Extended Attributes 315 The name argument is a null-terminated string that defines the name of the EA. The value argument is a p ...

316 Chapter 16 Removing an EA The removexattr(), lremovexattr(), and fremovexattr() system calls remove an EA from a file. The n ...