Create simple shell scripts

A system administrator needs to create a shell script that checks if the user 'jdoe' exists in the system and, if not, creates the user with a home directory. The script should also verify that the creation was successful. Which of the following script snippets correctly implements this logic?

A developer wrote a shell script that is intended to back up log files by copying all .log files from /var/log/myapp to /backup/logs. The script runs daily via cron but the backup folder is empty. The script contains the following line: `cp /var/log/myapp/*.log /backup/logs/`. What is the most likely reason the backup fails?

Which THREE of the following practices are recommended when creating simple shell scripts in a Red Hat Enterprise Linux environment to ensure reliability, security, and maintainability?

Refer to the exhibit. A junior admin runs this script as root, but it always prints 'httpd is running' even when httpd is stopped. What is the most likely cause?

You are a system administrator for a medium-sized company running Red Hat Enterprise Linux 8 on all servers. The development team has created a shell script that is supposed to be run nightly via cron to synchronize configuration files from a master server to multiple web servers. The script is located at /opt/scripts/sync_configs.sh and is owned by root. It uses rsync over SSH with key-based authentication. The script works perfectly when run manually by root, but when it runs via cron, the synchronization fails with the error 'Host key verification failed.' The script does not explicitly specify any SSH options. The cron job is configured in /etc/crontab as: `0 2 * * * root /opt/scripts/sync_configs.sh`. The SSH keys are stored in /root/.ssh/id_rsa and the known_hosts file contains the correct host key for the master server. What is the most likely cause of the failure, and what is the best course of action to resolve it?

Which TWO of the following are true about creating simple shell scripts in Red Hat Enterprise Linux?

You are a system administrator for a small company. The development team has created a shell script named 'deploy.sh' that automates deployment of a web application. The script is located at /home/devops/deploy.sh. The team reports that when they run the script with './deploy.sh' from the /home/devops directory, it fails with a 'Permission denied' error. However, running 'bash deploy.sh' works fine. Additionally, the script's first line is '#!/bin/bash' and the file permissions are '-rw-rw-r--'. The team wants to be able to run the script directly without typing 'bash'. Which of the following actions should you take to resolve the issue?

Arrange the steps to configure a logical volume snapshot named 'snap_lv_data' of logical volume 'lv_data'.

Match each package management command to its action.

An administrator writes a script that uses the 'set -e' option at the top. What is the primary effect of this option?

A system administrator needs to create a shell script that processes a list of hostnames stored in a file, one per line, and runs a command on each host. Which loop construct is most appropriate?

A developer wants to create a script that accepts a directory path as an argument and creates a timestamped backup of that directory. If no argument is provided, it should back up the current directory. How should the script handle the argument?

An administrator writes a script to check disk usage and send an alert if usage exceeds 80%. The script uses 'df -h /' and parses the output. To maintain portability and avoid common pitfalls, which approach is recommended?

A script needs to execute a command that might fail, but the script should continue. The administrator wants to capture the exit status for logging. Which code snippet correctly implements this?

A junior admin writes a script that uses functions. They notice that a variable set inside a function is not available after the function call. What is the likely cause and best practice?

A sysadmin creates a script to rotate log files. The script uses 'find /var/log -type f -name "*.log" -mtime +30 -exec gzip {} \;' but some log files are not compressed. The script runs as root. What is the most likely reason some files remain uncompressed?

A script uses 'read' to get user input and then performs an action based on the input. However, when the script is piped (e.g., './script.sh | othercommand'), the read command does not wait for input and the script continues with empty variable. How can this be fixed?

A complex script uses 'trap' to handle signals. The admin writes 'trap '' SIGINT' to ignore Ctrl+C, but later in the script they want to re-enable the default behavior. Which command restores the default behavior for SIGINT?

Which TWO of the following are valid ways to make a shell script executable?

Which THREE of the following are common practices to improve the reliability of shell scripts?

Which TWO of the following are correct statements about exit codes in shell scripts?

Consider the script in the exhibit. The script is run in a directory containing 'a.txt' and 'b.txt' but also has a subdirectory 'backup' with .txt files. What will be the output?

A developer runs the script shown in the exhibit and always sees 'Success' printed, even when the previous command fails. What is the most likely cause?

A user executes the script shown in the exhibit with './export_script.sh' and then runs 'echo $MY_VAR' in the same terminal. The output is empty. Why does this happen?

A script contains: lines=$(wc -l /etc/passwd); echo $((lines+1)). The output is unexpected. What is the problem?

A script has a syntax error. Which command will help identify the line number of the error without executing the script?

Which shell built-in can be used to read user input during script execution?

A script needs to read every line from a file and execute a command on each line. Which code block is correct and handles whitespace correctly?

Which TWO methods correctly create a variable containing the number of regular files in the current directory (excluding . and ..)?

Which THREE of the following are valid and recommended practices when writing shell scripts for RHEL?

Refer to the exhibit. The script produces the error shown. What is the most likely cause?

You are tasked with creating a script that reads a list of usernames from /tmp/users.txt, one per line, and creates a home directory for each user using `mkdir /home/$username`. The script is: #!/bin/bash while read username; do mkdir /home/$username done < /tmp/users.txt However, the script fails for usernames that contain spaces (e.g., 'john smith'). The error is 'mkdir: cannot create directory '/home/john': File exists' and then a separate directory for 'smith'. What is the best fix?

You maintain a script that performs a long-running task and must clean up temporary files if the script is interrupted. The script uses: #!/bin/bash tempfile=$(mktemp) trap "rm -f $tempfile" EXIT # long task sleep 100 You notice that if the script receives SIGINT (Ctrl+C), the temporary file is not removed. Investigation shows that the trap on EXIT is not executed on SIGINT. Which modification should be made?

A new intern created a script to display the current user's home directory: #!/bin/bash echo "Home directory: $home" The script outputs 'Home directory: ' with nothing after the colon. What is the most likely cause?

A system administrator writes a shell script to monitor disk usage and send an alert if any partition exceeds 80%. Which TWO of the following are best practices for implementing this script?

A system administrator writes the script shown. The /etc directory contains .conf files with spaces in their names (e.g., "my config.conf"). What is the most accurate description of the script's behavior?

An organization uses a shell script that runs daily via cron on a central management server to archive logs from 50 remote Red Hat Enterprise Linux servers. The script uses `scp` with SSH key-based authentication (passwordless) to transfer files. Recently, after a security team rotated the SSH host keys on all remote servers, the script started failing with 'Host key verification failed' errors. The administrator needs to restore automated log transfers without compromising security. The remote servers are in a controlled internal network, and the management server's `~/.ssh/known_hosts` file is not centrally managed. Which course of action should the administrator take?