bdftruncate

bdftruncate [ -t | -u ] [ -s | -c ] [ -f font_file ] [ -o output_file ]

-t
    Truncate unused Unicode encoding ranges. When specified, only Unicode ranges that contain actual characters in the font are kept. This is mutually exclusive with -u.

-u
    Do not truncate unused Unicode encoding ranges. All possible Unicode ranges are kept. This is the default behavior and mutually exclusive with -t.

-s
    Generate Unicode encoding ranges for a subset font. This means the output font will only declare ranges for characters that are present in the font. This is mutually exclusive with -c.

-c
    Generate Unicode encoding ranges for a full font. This means the output font will declare all possible Unicode encoding ranges, even if characters are not present in all parts of the range. This is the default behavior and mutually exclusive with -s.

-f font_file
    Specify the input BDF font file. If this option is omitted, bdftruncate reads from standard input.

-o output_file
    Specify the output BDF font file. If this option is omitted, bdftruncate writes to standard output.

The bdftruncate command is a utility designed for modifying Bitmap Distribution Format (BDF) font files, specifically concerning their Unicode encoding ranges. Its primary purpose is to either truncate unused Unicode encoding ranges or to generate specific ranges for font subsets. This is particularly useful for handling large CJK (Chinese, Japanese, Korean) fonts, where a full Unicode range might be excessively large. By truncating or defining specific ranges, bdftruncate helps in creating smaller, more efficient font files or subsets that contain only the necessary characters. It reads BDF font data from an input file (or standard input) and writes the processed data to an output file (or standard output). This tool is a component of the X.Org font utilities, playing a role in the broader ecosystem of font management and rendering on Unix-like systems, often preceding conversion to other formats like PCF using bdftopcf.

This command specifically modifies the internal Unicode encoding directives within BDF font files, not the actual glyph data. Improper use can lead to malformed font metadata, which might cause issues with character mapping or font rendering in applications. It is a specialized tool within the X.Org font utility ecosystem, primarily for managing font metadata rather than graphical content.

bdftruncate is a component of the X.Org project's font utilities, which are essential for managing and optimizing fonts within the X Window System environment. Its development stems from the need to efficiently handle large character sets, particularly those found in CJK (Chinese, Japanese, Korean) fonts, by allowing for the precise control and truncation of Unicode encoding ranges. This utility contributes to the broader goal of providing robust font management tools for developers and system administrators on Unix-like operating systems.

bdftopcf(1), bdfconv(1), mkfontdir(1), xset(1), fonttosfnt(1)