Time Complexity: Function libraries (sourcing scripts)
O(n)
0
0
Function libraries (sourcing scripts) in Bash Scripting - Time & Space Complexity
Understanding Time Complexity
When using function libraries by sourcing scripts in bash, it is important to understand how the execution time grows as the size of the library increases.
We want to know how sourcing affects the script's running time as more functions are added.
Scenario Under Consideration
Analyze the time complexity of the following code snippet.
# source a library of functions
source my_functions.sh
# call a function from the library
my_function "argument"
# continue with script tasks
This code sources a file containing many functions, then calls one function from it.
Identify Repeating Operations
Identify the loops, recursion, array traversals that repeat.
- Primary operation: Reading and loading all lines of the sourced script once.
- How many times: Exactly once per script execution, no loops or repeated traversals.
How Execution Grows With Input
As the size of the function library file grows, the time to read and load it grows proportionally.
| Input Size (n) | Approx. Operations |
|---|---|
| 10 lines | 10 operations to read and load |
| 100 lines | 100 operations to read and load |
| 1000 lines | 1000 operations to read and load |
Pattern observation: The time grows linearly as the library size increases.
Final Time Complexity
Time Complexity: O(n)
This means the time to source the script grows directly with the number of lines or functions in the library.
Common Mistake
[X] Wrong: "Sourcing a script only loads the functions I call, so time does not grow with library size."
[OK] Correct: When sourcing, the entire file is read and parsed, even if only one function is used later.
Interview Connect
Understanding how sourcing affects script performance helps you write efficient bash scripts and shows you can reason about script behavior beyond just coding.
Self-Check
"What if the sourced script used lazy loading or conditional function definitions? How would the time complexity change?"