and (Compute)

When To Use

Use and to apply a bitwise AND between every value of one column and a bitmask, row by row. This isolates the bits you care about in a packed status word — for example keeping only the low-order bits of a raw hardware register, or testing a single flag bit before translating it to a status. The mask is either a literal number or, with the $n syntax, the value of another column of the same row. When each bit of the word maps to its own status message, prefer perBitTranslation, which decodes all bits in one pass.

Syntax

sources:
  sensorStatus:
    type: snmpTable
    oid: 1.3.6.1.4.1.9999.1.2.1
    selectColumns: "ID,2"
    computes:
    # Keep only the 10 low-order bits of the raw status word
    - type: and
      column: 2
      value: 1023

Properties

Table Transformation Example

With column: 2 and value: 1023 (binary 1111111111), any bits above bit 9 are cleared:

5123 is binary 1010000000011; masking with 1023 keeps only the 10 low-order bits, leaving 3. 18 fits entirely within the mask and is unchanged.

Recommended Pattern

• Document the mask in binary in a comment (# 1023 = 1111111111, keep bits 0-9) so reviewers do not have to convert it mentally.
• Follow and with a translate compute to turn the isolated bit value into a readable status.
• To test one flag, mask with the bit's value (1, 2, 4, 8, …): the result is non-zero when the flag is set.
• Reach for perBitTranslation instead when several independent bits each carry their own meaning.

Common Mistakes

• Writing the mask in binary or hexadecimal notation while a plain decimal number is expected (1023, not 0b1111111111).
• Masking a column that is not an integer status word (decimal or textual values).
• Confusing and with a logical filter: it transforms values in place and never removes rows — use keepOnlyMatchingLines or excludeMatchingLines to filter.

Community Examples