Bash and Linux

The shell one-liners and scripts infra interviews expect. Grouped by pattern and tagged by role. Practise each one on LeetCode and tick it off here.

0 / 20 solved

Easy 0/9·Medium 0/11·Hard 0/0

Problem	Difficulty	Practice	Explanation	Solution
Show every ERROR line with its line number	Easy	—	Read	—
Print only valid phone numbers	Easy		Read	—
Find files that contain a leaked AWS access key	Medium	—	Read	—

Problem	Difficulty	Practice	Explanation	Solution
List users whose login shell is bash	Easy	—	Read	—
Total the bytes served in an access log	Easy	—	Read	—
Average response time per endpoint	Medium	—	Read	—
Transpose the rows and columns of a file	Medium		Read	—

Status	Problem	Difficulty	Practice	Explanation	Solution	Save
	Replace a config value in place	Easy	—	Read	—
	Strip comments and blank lines from a config	Medium	—	Read	—

Problem	Difficulty	Practice	Explanation	Solution
Count unique HTTP status codes	Easy	—	Read	—
Print the 3 most frequent IPs in an access log	Medium	—	Read	—
Word frequency count	Medium		Read	—

Problem	Difficulty	Practice	Explanation	Solution
Delete .tmp files older than 7 days	Easy	—	Read	—
Find files larger than 1 MiB, biggest first	Medium	—	Read	—
Find manifests using an image's :latest tag	Medium	—	Read	—

Problem	Difficulty	Practice	Explanation	Solution
Top 3 directories by size	Easy	—	Read	—
Top 3 processes by memory usage	Medium	—	Read	—
Find world-writable files	Medium	—	Read	—

Status	Problem	Difficulty	Practice	Explanation	Solution	Save
	Validate script arguments and exit with a usage code	Easy	—	Read	—
	Health-check a list of URLs and exit non-zero on failure	Medium	—	Read	—

Must-do problem (the last-minute revision list). Company tags appear only where a public interview report names that company.

grep and regexFinding the lines that matter in a log.0 / 3