Necessary Linux operation and maintenance: quick guide to get started with sort command

As an operation and maintenance engineer, processing logs and analyzing data is common.sortCommands are a magic tool for efficiently sorting text in Linux, which can quickly sort, deduplicate and count file content. This article uses the simplest way to help you master itsortcore usage.

1. Basic sorting: instantly kill messy text

# By default, sort in ascending order in dictionary order (file/input stream)
 sort

 # Example: Sort log time (assuming the first column is time)
 sort /var/log/nginx/

2. Practical parameters: precise control sorting

Sort by numerical value
When processing numbers, be sure to use-n, avoid "10" being behind "2"!
```
sort -n 
```
Order in reverse order
-rImplement from large to small or from Z to A:
```
sort -nr large_numbers.txt # Numerical inverse order
```
Sort by specified column
use-kSelect the column,-tSpecify delimiters (such as commas, colon):
```
# Sort CSV files by column 2 (numerical)
 sort -t',' -k2n
```
Go to the heavy
-uQuickly clean up duplicate rows (sorted first):
```
sort -u  > unique_ips.txt
```
Ignore case
-fLet "Apple" and "apple" be treated as the same:
```
sort -f mixed_case.txt
```

3. Practical operation and maintenance scenarios

1. Statistics log IP access frequency

cat  | awk '{print $1}' | sort | uniq -c | sort -nr

Steps to disassemble：
- awkExtract IP columns
- sortSort souniqstatistics
- uniq -ccount
- sort -nrReverse order by visits

2. Sort processes by memory usage

ps aux --sort=-%mem | head -n 10

--sort=-%memEquivalent tosort -k4nr(In reverse order of memory in column 4)

3. Merge multiple sorted files

sort -m   >

-m(merge) is much more efficient than reordering large files

4. Avoiding pits

Performance optimization：
Useful when processing oversized files-TSpecify temporary directories (avoid insufficient default partition space):
```
sort -T /mnt/big_disk/tmp/ huge_file.txt
```
Locale：
When not English sorting exceptions, setLC_ALL=CDisable localization rules:
```
LC_ALL=C sort 
```
Stable sorting：
If you need to preserve the original order of equal value rows, add-s（stable sort）。

5. Summary

sort + awk/uniqThe combination of commands is a Swiss army knife for operation and maintenance analysis data. Master the core parameters:
-n(value),-k(List),-t(separator),-r(Reverse order),-u(Deduplication) can meet 90% of sorting needs.

remember:Before processing data, use it firstheadorTest the command to avoid direct operation of large files to overturn!