nushell/docs/commands/where.md
2019-11-30 14:24:39 +13:00

5.3 KiB

where

This command filters the content of a table based on a condition passed as a parameter, which must be a boolean expression making use of any of the table columns. Other commands such as ls are capable of feeding where with their output through pipelines.

Where has two general forms:

  • where <column_name> <comparison> <value>
  • where <column_name>

Where with comparison

In the first form, where is passed a column name that the filter will run against. Next, is the operator used to compare this column to its value. The following operators are supported:

  • < (less than)
  • <= (less than or equal)
  • > (greater than)
  • >= (greater than or equal)
  • != (not equal)
  • == (equal)

Strings have two additional operators:

  • =~ (fuzzy match to allow)
  • !~ (fuzzy match to not allow)

Dates can also be compared using the duration types. For example, where accessed > 2w will check the date in accessed to see if it's greater than 2 weeks ago. Durations currently allow these abbreviations:

  • 1s (one second)
  • 1m (one minute)
  • 1h (one hour)
  • 1d (one day)
  • 1w (one week)
  • 1M (one month)
  • 1y (one year)

Boolean check

Where with the form | where readonly is used to check boolean values. For example, the command ls --full | where readonly will list only those files that are readonly.

Usage

> [input-command] | where [condition]

Examples

> ls | where size > 4kb
━━━┯━━━━━━━━━━━━┯━━━━━━┯━━━━━━━━━┯━━━━━━━━━━━━━┯━━━━━━━━━━━━━┯━━━━━━━━━━━━━
 # │ name       │ type │ size    │ created     │ accessed    │ modified 
───┼────────────┼──────┼─────────┼─────────────┼─────────────┼─────────────
 0 │ Cargo.lock │ File │ 87.2 KB │ 7 hours ago │ 7 hours ago │ 7 hours ago 
 1 │ README.md  │ File │ 19.5 KB │ 7 hours ago │ 7 hours ago │ 7 hours ago 
 2 │ Cargo.toml │ File │  4.7 KB │ 7 hours ago │ 7 hours ago │ 7 hours ago 
━━━┷━━━━━━━━━━━━┷━━━━━━┷━━━━━━━━━┷━━━━━━━━━━━━━┷━━━━━━━━━━━━━┷━━━━━━━━━━━━━
> ps | where cpu > 0
━━━┯━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━
 # │ pid   │ name                  │ status   │ cpu 
───┼───────┼───────────────────────┼──────────┼───────────────────
 01546 │ Xorg                  │ Sleeping │ 10.65405000000000 
 11769 │ gnome-shell           │ Sleeping │ 5.271094000000000 
 22153 │ gnome-terminal-server │ Sleeping │ 5.193664000000000 
 313556 │ nu_plugin_ps          │ Sleeping │ 40.70250000000000 
━━━┷━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━
> ls | where accessed <= 1w
━━━┯━━━━━━━━━━━━━━━┯━━━━━━━━━━━┯━━━━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━
 # │ name          │ type      │ size     │ accessed   │ modified 
───┼───────────────┼───────────┼──────────┼────────────┼────────────
 0 │ Cargo.toml    │ File      │   4.7 KB │ 2 days ago │ 2 days ago 
 1 │ target        │ Directory │   4.1 KB │ 2 days ago │ 2 days ago 
 2 │ Makefile.toml │ File      │    449 B │ 4 days ago │ 4 days ago 
 3 │ README.md     │ File      │  19.5 KB │ 2 days ago │ 2 days ago 
 4 │ Cargo.lock    │ File      │ 170.7 KB │ 2 days ago │ 2 days ago 
 5 │ crates        │ Directory │   4.1 KB │ 2 days ago │ 2 days ago 
 6 │ TODO.md       │ File      │   1.3 KB │ 2 days ago │ 2 days ago 
━━━┷━━━━━━━━━━━━━━━┷━━━━━━━━━━━┷━━━━━━━━━━┷━━━━━━━━━━━━┷━━━━━━━━━━━━
> ls | where name =~ "yml"
━━━━━━━━━━━━━┯━━━━━━┯━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━
 name        │ type │ size  │ accessed   │ modified 
─────────────┼──────┼───────┼────────────┼────────────
 .gitpod.yml │ File │ 780 B │ a week ago │ a week ago 
━━━━━━━━━━━━━┷━━━━━━┷━━━━━━━┷━━━━━━━━━━━━┷━━━━━━━━━━━━