#csplit

Version 0.2.0 behavior is documented here. The support record separates local verification from published MoonX behavior; moonx examples use registry releases.

Split a file into sections at line numbers or basic regular expressions:

moonx cli/csplit input.txt 10 20
moonx cli/csplit -s -f section- input.txt '/^Chapter/' '{*}'

NUMBER splits before that absolute line; /REGEXP/ splits before a matching line and %REGEXP% discards the preceding section. Regex delimiters may be followed by a positive or negative line offset. {N} repeats the preceding pattern N additional times. Regex {*} repeats through the remaining input; numeric repetitions that reach beyond the last line report an error. The first operand - reads stdin. All input bytes, including NUL and an unterminated final line, are preserved in selected fragments.

Files are named xx00, xx01, … . -f/--prefix changes the prefix and -n/--digits sets the minimum number of suffix digits. Byte counts are printed for created files unless -s/--silent or -q/--quiet is selected. -z/--elide-empty-files omits empty fragments. Split failures remove the files created by that invocation unless -k/--keep-files is used.

-b/--suffix-format replaces the default digits with exactly one d/i/u/o/x/X integer conversion, literal text and %%. Width, precision, left/zero padding and applicable alternate/thousands flags follow the GNU C profile. Repeated formats use the last; -b determines layout independently of -n ordering. Invalid formats fail before file creation. Windows ordinary filesystem paths trim trailing spaces and dots. A generated name with either ending is therefore refused with status 2 before reading input; it never silently creates a differently named fragment. Verbatim-name support requires verified Native/Wasm creation, reading and observation of those exact names.

--suppress-matched omits the line at the offset-adjusted split boundary for regex, ignored regex and numeric patterns. Empty elision reuses the next output suffix; suppression preserves the separate regex-search cursor.

Input is buffered. The shared C-byte BRE matcher compiles each expression once and supports capture backreferences, byte classes and word assertions. Repeated nullable captures follow the tested GNU candidate and capture-register selection, including counted repeats and references. See the workspace support record. Existing output paths are refused. Locale-sensitive matching is outside the selected profile. --help and --version provide command information.

#Standalone metadata

Standalone --version prints exactly csplit 0.2.0 followed by one newline. Standalone --help starts with Usage: csplit, lists both metadata options, and ends with a newline. Both write to stdout, leave stdin unread, and exit with status 0. Exact-version publication and verification remain recorded separately in the support record.