This XK0-005 practice question tests your understanding of troubleshooting. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A user runs a command and receives the error 'bash: myapp: command not found'. The administrator confirms the binary exists in /usr/local/bin. Which environment variable should be checked?
HOME
Not relevant; PATH is the correct variable.
SHELL
Why wrong: Indicates the current shell, not search paths.
LD_LIBRARY_PATH
Why wrong: Used for shared library search, not executables.
PATH
Why wrong: Lists directories for executable search.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
HOME
The PATH environment variable defines the directories the shell searches for executables when a command is typed. Even though the binary exists in /usr/local/bin, if that directory is not listed in PATH, the shell will not find it and will return 'command not found'. Checking and correcting PATH resolves this issue.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
HOME
Why this is correct
Not relevant; PATH is the correct variable.
Related concept
Read the scenario before looking for a memorised answer.
SHELL
Why it's wrong here
Indicates the current shell, not search paths.
LD_LIBRARY_PATH
Why it's wrong here
Used for shared library search, not executables.
PATH
Why it's wrong here
Lists directories for executable search.
Common exam traps
The trap here is that candidates may confuse PATH with LD_LIBRARY_PATH or assume the binary's existence alone guarantees it can be run, overlooking the shell's directory search mechanism.
Detailed technical explanation
The PATH variable is a colon-separated list of directories (e.g., /usr/local/bin:/usr/bin:/bin). When a command is entered, the shell uses execvp() or similar system calls that rely on PATH to locate the binary. A common subtlety is that the current directory (.) is often not in PATH for security reasons, so users must use ./myapp to run local binaries.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
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FAQ
Troubleshooting — This question tests Troubleshooting — Read the scenario before looking for a memorised answer..
The correct answer is: HOME — The PATH environment variable defines the directories the shell searches for executables when a command is typed. Even though the binary exists in /usr/local/bin, if that directory is not listed in PATH, the shell will not find it and will return 'command not found'. Checking and correcting PATH resolves this issue.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This XK0-005 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the XK0-005 exam.
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