BATsh-0.08

Changes for version 0.08 - 2026-07-23

NEW SH BUILTINS: let, type and command are now evaluated internally in pure Perl. Previously all three fell through to the external command path and were handed to whatever real shell happened to exist -- which failed on systems without that shell and defeated BATsh's "no external shell required" design.
- let EXPR [EXPR ...] -- arithmetic evaluation, reusing the same evaluator as $(( )), so assignments and ++/-- write back to the variable store. Exit status is 0 when the last expression is non-zero and 1 when it is zero (the (( )) convention).
- type [-t|-p] NAME ... -- report how each NAME resolves, in bash's precedence order: alias, keyword, function, builtin, then an executable on PATH. -t prints the one-word kind; -p prints the path of an external file.
- command [-v|-V] NAME [ARG ...] -- run NAME bypassing any shell function of that name; -v prints how NAME would be invoked (the portable `command -v foo >/dev/null` feature-detection idiom) and -V prints a verbose, type-style description.
- New regression test t/0027-let-type-command.t (22 checks).
MORE SH BUILTINS / ATTRIBUTES (pure Perl):
- umask [-S] [MODE] -- print or set the file-creation mask; -S prints the symbolic form. MODE may be octal (022) or symbolic (u=rwx,g=rx,o=rx, with +/- operations). The shell keeps its own copy of the mask so "umask MODE; umask" round-trips on every platform (native Win32 Perl's umask() always reports 0), and pushes a set value to the OS umask so it still affects file modes where the OS honours it.
- hash [-r] [NAME ...] -- BATsh keeps no location cache, so the maintenance forms are successful no-ops; "hash NAME" verifies NAME is on PATH. (Previously umask and hash fell through to an external shell and produced "Can't exec" errors.)
- readonly [-p] [NAME[=VALUE] ...] -- mark a variable read-only; a later assignment or unset is refused with a non-zero status. The readonly attribute is enforced at every assignment path (VAR=val, prefix VAR=val cmd, export, declare) and is script-scoped (reset between top-level runs).
- mapfile / readarray [-t] [-d DELIM] [-n COUNT] [-O ORIGIN] [-s SKIP] [ARRAY] -- read lines of standard input into an indexed array (default MAPFILE).
declare -i / -r: the integer attribute now evaluates a variable's right-hand side as arithmetic ("declare -i n=3+4" stores 7, and the attribute sticks so a later "n=2*5" stores 10); -r marks the variable read-only. Previously "declare -i" stored its initialiser literally. A quoted initialiser containing spaces now works too, e.g. declare -i s="1 + 2" (the scalar value is parsed quote-aware).
- New regression test t/0029-sh-attrs-mapfile.t (22 checks).
printf REWRITTEN (SH mode): the builtin is now a faithful pure-Perl implementation. Previously it understood only \n and \t, split quoted arguments on whitespace (losing "a b" style operands), did not recycle the format, and leaked Perl "Redundant argument" / "isn't numeric" warnings to STDERR. It now supports:
- format recycling -- the format is reused until the arguments are exhausted, so printf '%s\n' a b c prints three lines;
- the full conversion set %d %i %o %u %x %X %e %E %f %g %G %c %s %b %q %%, with flags, field width and precision, and the dynamic %*d width/precision form;
- %b (backslash escapes interpreted in the argument, with \c ending output) and %q (shell-reusable quoting);
- the complete C/POSIX escape set in the format string (\\ \a \b \f \n \r \t \v \e \NNN octal \xHH hex);
- -v VAR to store the result in a shell variable instead of printing;
- quiet, bash-like handling of a non-numeric numeric argument (treated as 0, no STDERR noise).
- New regression test t/0028-sh-printf.t (21 checks).
FIX (SH external commands): a command that could not be launched (system() returned -1) now reports exit status 127 ("command not found"), as bash does. The previous ($rc >> 8) arithmetic on -1 produced a nonsensical huge status.
DOC FIX (README): "getopts" was still listed under "does not implement" although it has been a supported builtin since 0.07. The stale entry is removed and getopts is listed with the other 0.07 builtins.
QA / TESTS: this release also hardens the distribution's own self-checks against two blind spots.
t/9020-perl5compat.t now scans the whole distribution rather than only lib/*.pm. It walks lib/, t/, bin/ and eg/ with File::Find (core since Perl 5.000) and applies the Perl 5.005_03 compatibility checks (3-argument open, lexical file and directory handles, our/say/state, defined-or, and so on) to every .pm, .pl and .t file. Previously only four lib modules were examined, so a Perl 5.6+ construct in a test, script or example could slip past. The scanner excludes itself -- it necessarily contains the very constructs it detects -- and ignores matches that occur only in comments.
t/9061-readme-refs.t (new): checks that every in-distribution file the README refers to (eg/, doc/, bin/, lib/ and t/ paths) actually exists on disk. This is the reverse of the existing MANIFEST-driven README check and guards against a documented-but-absent example.