sort -r: Reverse and Top-N Selection

sort -r reverses the comparison so output runs from highest to lowest.

To find the biggest or most frequent items, sort descending and take the head. -r flips whatever order you asked for.

What it does

sort -r reverses the result of the comparison, producing descending order. It applies on top of other modifiers, so -nr sorts numerically descending and a plain -r sorts strings in reverse collation order.

Common usage

Terminal

sort -nr counts.txt | head -5        # five largest counts
uniq -c log.txt | sort -nr | head    # most frequent lines
du -sh */ | sort -hr                  # largest dirs, human sizes

Options

Flag	What it does
-r	Reverse the sort order
-n	Numeric: -nr is descending by value
-h	Human-readable sizes: -hr for largest first
-k <pos>	Reverse can attach per key, e.g. -k2,2nr

In CI

The classic "top offenders" pipeline is sort | uniq -c | sort -nr | head. Build it once and reuse it for log frequency, file sizes, or test timings.

Common errors in CI

Reverse string order depends on the locale collation, so -r without LC_ALL=C can order punctuation and case unexpectedly; set LC_ALL=C for byte order. Forgetting -n in -r means a string reverse, so "9" sorts after "10"; use -nr for numbers.

Related guides

sort -n: Numeric Sorting in CI Pipelinessort -n orders lines by numeric value instead of as strings. Reference for -n, -g, and the locale and leading… sort -h: Sort Human-Readable Sizessort -h orders human-readable sizes like 1K, 2M, 3G correctly. Reference for -h, pairing with du -h, and the… uniq -c: Count Repeated Linesuniq -c prefixes each line with how many times it repeated. Reference for -c, the must-be-sorted rule, and th… head -n: First N Lines of Outputhead -n prints the first N lines of input. Reference for -n, the negative -n form, multiple files, and the SI…