LPI 101-500 Exam With Confidence Using Practice Dumps

 The find command is used to search for files and directories that match certain criteria. The -uid option specifies the numeric user ID of the owner of the file or directory, while the -user option specifies the name of the owner. The -print option prints the full file name of the matching file or directory to the standard output. Therefore, both find /tmp -uid root -print and find /tmp -user root -print will print all files and directories within the /tmp directory or its subdirectories which are also owned by the user root. The other options are either invalid or do not perform the desired task. The -path option matches the whole path name, not just the starting directory. The -print option is implied if no other action is specified, but it is good practice to include it for clarity. References:

• LPIC-1 Exam 101 Objectives, Topic 103: GNU and Unix Commands, 103.4 Use streams, pipes and redirects
• LPIC-1 Linux Administrator 101-500 Exam FAQ, LPIC-1 Exam 101 Objectives, GNU and Unix Commands (Total Weight: 25)

 This option to the find command is useful if the filenames contain spaces when redirecting the output of find to the xargs command. The syntax of the option is:

find [where to start searching from] [expression determines what to find] -print0

The -print0 option tells the find command to print the full file name on the standard output, followed by a null character (ASCII code 0) instead of the newline character. This allows file names that contain spaces or other special characters to be correctly interpreted by the xargs command, which can use the -0 option to read items from the standard input that are terminated by a null character. The syntax of the xargs command with the -0 option is:

xargs -0 [command]

The -0 option tells the xargs command to expect the items from the standard input to be separated by a null character, and to execute the command using the items as arguments.

Therefore, the command find … -print0 | xargs -0 … will search for files and directories using the find command, print the results with a null character as the separator, pipe the output to the xargs command, which will read the items with a null character as the separator, and execute another command using the items as arguments. This will avoid any problems with filenames that contain spaces or other special characters.

The other options are incorrect for the following reasons:

• A, -rep-space: This option does not exist in the find command. There is no option to replace spaces in the filenames with another character in the find command. The command will report an error and exit.
• B, -printnul: This option does not exist in the find command. There is a similar option, -print0, which prints the filenames with a null character as the separator, but -printnul is not a valid option. The command will report an error and exit.
• C, -nospace: This option does not exist in the find command. There is no option to ignore spaces in the filenames in the find command. The command will report an error and exit.
• D, -ignore-space: This option does not exist in the find command. There is no option to ignore spaces in the filenames in the find command. The command will report an error and exit.

References:

• How to Use the find Command in Linux - How-To Geek
• find command in Linux with examples - GeeksforGeeks
• find(1) - Linux manual page - man7.org
• [xargs command in Linux with examples - GeeksforGeeks]
• [How to Use the xargs Command on Linux - How-To Geek].

The tee command reads from standard input and writes to both standard output and one or more files1. Therefore, the command myapp | tee file1.log will send the output of the program myapp to both the terminal and the file file1.log. The other commands will either fail to write to both standard output and file, or write the wrong output. For example, the command cat < myapp | cat > file1.log will try to read the file myapp as input and write it to the file file1.log, but it will not display anything on the terminal. The command myapp 0>&1 | cat > file1.log will redirect the standard input of myapp to its standard output, and then pipe it to the file file1.log, but it will not display anything on the terminal. The command myapp | cat > file1.log will pipe the output of myapp to the file file1.log, but it will not display anything on the terminal. The command tee myapp file1.log will try to read from standard input and write to both the file myapp and the file file1.log, but it will not execute the program myapp. References:

• [LPI Linux Essentials - 1.3 Basic Editing]
• [LPI Linux Essentials - 1.4 I/O Redirection]
• [LPI Linux Essentials - 1.5 Manage Simple Partitions and Filesystems]