Linux三剑客：grep、awk、sed

发表于 2019-11-11 更新于 2023-03-01 分类于 Linux
本文字数： 249 阅读时长 ≈ 1 分钟

grep

global search regular expression(RE) and print out the line

基于正则表达式查找满足条件的行

grep 语法

grep pattern file
grep -i pattern file #忽略大小写
grep -v pattern file #不显示匹配的行
grep -o pattern file #把每个匹配的内容用独立的行显示
grep -E pattern file #使用扩展正则表达式
grep -A -B -C pattern file #打印命中数据的上下文
grep pattern -r dir / #递归搜索

awk

名字来源于三个作者的名字简称

根据定位到的数据行处理其中的分段

awk 语法

awk 'pattern{action}'
awk 'BEGIN{}END{}' #开始和结束
awk '/Running/' #正则匹配
awk '/aa/,/bb/' #区间选择
awk '$2~/xxx/' #字段匹配
awk 'NR==2' #取第二行
awk 'NR>1' #去掉第一行

sed

steam editor

根据定位到的数据行修改数据

sed 语法

sed [addr]X[options]
-e 表达式
sed -n '2p' #打印第二行
sed 's#hello#world#' #修改
-i #直接修改源文件
-E #扩展表达式
--debug #调试

MongoDB常用查询

发表于 2019-11-08 更新于 2023-03-01 分类于 MongoDB
本文字数： 65 阅读时长 ≈ 1 分钟

模糊查询

mongoDB 支持正则表达式

1	db.products.find( { sku: { $regex: /789$/ } } )

1	SELECT * FROM products WHERE sku like "%789";

排序

1	{ $sort: { <field1>: <sort order>, <field2>: <sort order> ... } }

1 to specify ascending order. 顺序
-1 to specify descending order. 倒序

示例：

db.users.aggregate(
   [
     { $sort : { age : -1, posts: 1 } }
   ]
)

分页

1	db.COLLECTION_NAME.find().limit(NUMBER).skip()

MongoDB Operators

发表于 2019-11-07 更新于 2023-03-01 分类于 MongoDB
本文字数： 624 阅读时长 ≈ 2 分钟

Comparison Query Operators

Name	Description
`$eq`	Matches values that are equal to a specified value.
`$gt`	Matches values that are greater than a specified value.
`$gte`	Matches values that are greater than or equal to a specified value.
`$in`	Matches any of the values specified in an array.
`$lt`	Matches values that are less than a specified value.
`$lte`	Matches values that are less than or equal to a specified value.
`$ne`	Matches all values that are not equal to a specified value.
`$nin`	Matches none of the values specified in an array.

Logical Query Operators

Name	Description
`$and`	Joins query clauses with a logical `AND` returns all documents that match the conditions of both clauses.
`$not`	Inverts the effect of a query expression and returns documents that do not match the query expression.
`$nor`	Joins query clauses with a logical `NOR` returns all documents that fail to match both clauses.
`$or`	Joins query clauses with a logical `OR` returns all documents that match the conditions of either clause.

Element Query Operators

Name	Description
`$exists`	Matches documents that have the specified field.
`$type`	Selects documents if a field is of the specified type.

Evaluation Query Operators

Name	Description
`$expr`	Allows use of aggregation expressions within the query language.
`$jsonSchema`	Validate documents against the given JSON Schema.
`$mod`	Performs a modulo operation on the value of a field and selects documents with a specified result.
`$regex`	Selects documents where values match a specified regular expression.
`$text`	Performs text search.
`$where`	Matches documents that satisfy a JavaScript expression.

Geospatial Query Operators

Query Selectors

Name	Description
`$geoIntersects`	Selects geometries that intersect with a GeoJSON geometry. The 2dsphere index supports `$geoIntersects`.
`$geoWithin`	Selects geometries within a bounding GeoJSON geometry. The 2dsphere and 2d indexes support `$geoWithin`.
`$near`	Returns geospatial objects in proximity to a point. Requires a geospatial index. The 2dsphere and 2d indexes support `$near`.
`$nearSphere`	Returns geospatial objects in proximity to a point on a sphere. Requires a geospatial index. The 2dsphere and 2d indexes support `$nearSphere`.

Geometry Specifiers

Name	Description
`$box`	Specifies a rectangular box using legacy coordinate pairs for `$geoWithin` queries. The 2d index supports `$box`.
`$center`	Specifies a circle using legacy coordinate pairs to `$geoWithin` queries when using planar geometry. The 2d index supports `$center`.
`$centerSphere`	Specifies a circle using either legacy coordinate pairs or GeoJSON format for `$geoWithin` queries when using spherical geometry. The 2dsphere and 2d indexes support `$centerSphere`.
`$geometry`	Specifies a geometry in GeoJSON format to geospatial query operators.
`$maxDistance`	Specifies a maximum distance to limit the results of `$near` and `$nearSphere` queries. The 2dsphere and 2d indexes support `$maxDistance`.
`$minDistance`	Specifies a minimum distance to limit the results of `$near` and `$nearSphere` queries. For use with `2dsphere` index only.
`$polygon`	Specifies a polygon to using legacy coordinate pairs for `$geoWithin` queries. The 2d index supports `$center`.
`$uniqueDocs`	Deprecated. Modifies a `$geoWithin` and `$near` queries to ensure that even if a document matches the query multiple times, the query returns the document once.

Array Query Operators

Name	Description
`$all`	Matches arrays that contain all elements specified in the query.
`$elemMatch`	Selects documents if element in the array field matches all the specified `$elemMatch` conditions.
`$size`	Selects documents if the array field is a specified size.

Bitwise Query Operators

Name	Description
`$bitsAllClear`	Matches numeric or binary values in which a set of bit positions all have a value of `0`.
`$bitsAllSet`	Matches numeric or binary values in which a set of bit positions all have a value of `1`.
`$bitsAnyClear`	Matches numeric or binary values in which any bit from a set of bit positions has a value of `0`.
`$bitsAnySet`	Matches numeric or binary values in which any bit from a set of bit positions has a value of `1`.