Filter

filter_first¶

Return the first line of stdin.

Exit codes¶

• 0: Always

Output on stdout¶

• First line of input

filter_not_first¶

Return all lines of stdin except the first.

Exit codes¶

• 0: Always

Output on stdout¶

• All input lines after the first

filter_last¶

Return the last line of stdin.

Exit codes¶

• 0: Always

Output on stdout¶

• Last line of input

filter_not_last¶

Return all lines of stdin except the last.

Exit codes¶

• 0: Always

Output on stdout¶

• All input lines except the last

filter_matching¶

Return only lines from stdin matching a given pattern.

Arguments¶

• $1 (string): The pattern to match against

Exit codes¶

• 0: Always

Output on stdout¶

• Lines matching the pattern

filter_not_matching¶

Return only lines from stdin that do not match a given pattern.

Arguments¶

• $1 (string): The pattern to exclude

Exit codes¶

• 0: Always

Output on stdout¶

• Lines not matching the pattern

match_at_most_one¶

Pass stdin through only if it contains at most one line; fail if more.

Exit codes¶

• 0: Zero or one line present
• 1: More than one line present

Output on stdout¶

• The single input line, or nothing if more than one line was present

match_at_least_one¶

Pass stdin through only if it contains at least one non-empty line.

Exit codes¶

• 0: At least one line present
• 1: No lines present

Output on stdout¶

• Input passed through unchanged

match_exactly_one¶

Pass stdin through only if it contains exactly one non-empty line.

Exit codes¶

• 0: Exactly one line present
• 1: Zero or more than one line present

Output on stdout¶

• The single input line

strip_trailing_newline¶

Strip the trailing newline from stdin output.

Exit codes¶

• 0: Always

Output on stdout¶

• Input with no trailing newline