Sorting and columns · ⁨排序与列⁩ — Linux & the command line

English

Putting lines in order

sort arranges lines alphabetically (or, with -n, as numbers):

sort -r reverses the order; sort -n is for lists of numbers.

中文

把各行排好序

sort 把各行按字母顺序排列(加上 -n 则按数字排列):

sort names.txt

sort -r 反转顺序;sort -n 用于数字列表。

English

Removing duplicates

uniq removes neighbouring repeated lines. Because it only looks at neighbours, you usually sort first:

Add uniq -c to also count how many times each line appeared.

中文

去除重复

uniq 会去掉相邻的重复行。因为它只看相邻的行,所以你通常要先 sort:

sort names.txt | uniq

加上 uniq -c,还能统计每一行出现了多少次。

Explore · ⁨探索⁩

sort, then uniq · ⁨先 sort,再 uniq⁩

uniq only sees neighbours — sort first, so the duplicates sit together. · ⁨uniq 只看相邻行 —— 先 sort,重复的行才会挨在一起。⁩

English

Picking out columns

Many files have columns separated by a character — a comma, a colon, a tab.
cut pulls out the columns you want. -d sets the delimiter, -f the field:

That takes the first field of each name:age line — the names.

中文

取出某一列

很多文件的各列之间用某个字符分隔 —— 逗号、冒号或制表符。
cut 取出你想要的列。-d 设置分隔符,-f 设置字段:

cut -d : -f 1 people.txt

这会取每行 name:age 的第一个字段 —— 也就是名字。

English

Common mistakes

sort is alphabetical; sort -n sorts numbers correctly.
cut needs the right delimiter with -d.

中文

常见错误

sort 按字母排序;sort -n 才能正确排数字。
cut 要用 -d 指定正确的分隔符。

Get a tidy, de-duplicated list of names. Pipe sort into · ⁨ 生成 ⁩uniq: sort names.txt | uniq. · ⁨得到一份整洁、去重后的名字列表。把 sort 接到 uniq:sort names.txt | uniq。⁩

people.txt has name:age on each line. Pull out just the names with cut -d : -f 1 people.txt. · ⁨people.txt 每行是 name:age。用 cut -d : -f 1 people.txt 只取出名字这一列。⁩