LPI 010-160 Exam With Confidence Using Practice Dumps

 A typical shell script is a text file that contains a series of commands or instructions that can be executed by a shell interpreter. A shell script usually has the executable permission bit set, which means that it can be run as a program by the user or another program. A shell script also starts with the two character sequence #!, which is called a shebang or a hashbang. This sequence tells the operating system which shell interpreter to use to run the script. For example, #!/bin/bash indicates that the script should be run by the bash shell. References:

• Linux Essentials - Linux Professional Institute (LPI) 1
• Linux Essentials - Linux Professional Institute Certification Programs 2

The correct command to search for the file foo.txt under the directory /home is find /home –name foo.txt. This command uses the find command, which is used to search for files and directories that match certain criteria. The first argument, /home, specifies the starting point of the search. The second argument, -name, indicates that the search is based on the name of the file or directory. The third argument, foo.txt, is the name of the file to be searched for. The find command will recursively search all the subdirectories under /home and print the path of any file or directory that matches the name foo.txt.

The other commands are incorrect for various reasons:

• A. search /home –file foo.txt is incorrect because there is no such command as search in Linux. The correct command for searching files and directories is find.
• B. search /home foo.txt is incorrect because, as mentioned above, there is no search command in Linux. Also, this command does not use any option to specify the search criteria, such as -name, -type, -size, etc.
• C. find /home – file foo.txt is incorrect because the option -file is not valid. The correct option for specifying the type of file or directory is -type, followed by a letter that indicates the type, such as f for regular file, d for directory, l for symbolic link, etc. For example, find /home -type f -name foo.txt would search for a regular file named foo.txt under /home.
• E. find /home foo.txt is incorrect because this command does not use any option to specify the search criteria, such as -name, -type, -size, etc. This command will search for any file or directory that has foo.txt as part of its name, not exactly as its name. For example, this command will also match a file named barfoo.txt or a directory named foo.txt.bak.

References: : find command in Linux with examples - GeeksforGeeks : 15 Super Useful Examples of Find Command in Linux

 The reason why the script.sh does not display the content of the variable MYVAR is that the variable is not exported to the environment of the script. When a script is executed, it runs in a separate process that inherits the environment variables from the parent process, but not the shell variables. A shell variable is a variable that is defined and visible only in the current shell session, while an environment variable is a variable that is exported to the environment and visible to all processes that run in that environment1.

To make a shell variable an environment variable, we need to use the export command. The export command takes a shell variable name and adds it to the environment of the current shell and any subshells or processes that are created from it2. For example, to export the variable MYVAR with the value value, we can use:

export MYVAR=value

This will make the variable MYVAR available to the script.sh when it is executed, and the script will print the value of MYVAR as expected. Alternatively, we can also use the export command with the -n option to remove a variable from the environment, or with the -p option to list all the environment variables2.

The other options are not valid ways to set MYVAR as an environment variable. The !MYVAR=value option is not a valid syntax for setting a variable in bash. The env MYVAR=value option will run the env command with the MYVAR=value argument, which will print the environment variables with the addition of MYVAR=value, but it will not affect the current shell or the script.sh3. The MYVAR=value option will set MYVAR as a shell variable, but not as an environment variable, so it will not be visible to the script.sh1. The $MYVAR=value option will try to set the variable whose name is the value of MYVAR to the value value, which is not what we want4. References:

• Linux Essentials Exam Objectives, Version 1.6, Topic 103.1, Weight 2
• Linux Essentials Certification Guide, Chapter 3, Page 51-52
• env(1) - Linux manual page
• Bash Variables - LinuxConfig.org