Add rpmlua wrapper command for running our Lua interpreter standalone

Being able to run stuff easily in rpm context helps developing and debugging
scriptlets and macros too. Supports running one-liner statements from
the cli, regular scripts and an interactive session.

This is placed into a separate executable for, well, separation and
simplicity, but it'll also give us means to link to readline without
dragging that to main rpm dependencies (but that's left for later).

2 files changed, 72 insertions, 1 deletions

diff --git a/docs/man/Makefile.am b/docs/man/Makefile.am
index 7695586e8..216b85bcd 100644
--- a/docs/man/Makefile.am
+++ b/docs/man/Makefile.am
@@ -9,10 +9,11 @@ EXTRA_DIST += gendiff.1.md
 
 man_man8dir = $(mandir)/man8
 man_man8_DATA = rpm.8 rpm-misc.8 rpmbuild.8 rpmdeps.8 rpmgraph.8 rpm2cpio.8
-man_man8_DATA += rpmdb.8 rpmkeys.8 rpmsign.8 rpmspec.8
+man_man8_DATA += rpmdb.8 rpmkeys.8 rpmsign.8 rpmspec.8 rpmlua.8
 
 EXTRA_DIST += rpm.8.md rpm-misc.8.md rpmbuild.8.md rpmdeps.8.md rpmgraph.8.md
 EXTRA_DIST += rpm2cpio.8.md rpmdb.8.md rpmkeys.8.md rpmsign.8.md rpmspec.8.md
+EXTRA_DIST += rpmlua.8.md
 
 # Package generated man pages
 EXTRA_DIST += $(man_man1_DATA)
diff --git a/docs/man/rpmlua.8.md b/docs/man/rpmlua.8.md
new file mode 100644
index 000000000..52210bd27
--- /dev/null
+++ b/docs/man/rpmlua.8.md
@@ -0,0 +1,70 @@
+---
+date: 17 December 2021
+section: 8
+title: RPMLUA
+---
+
+NAME
+====
+
+rpmlua - RPM Lua interpreter
+
+SYNOPSIS
+========
+
+**rpmlua** {**-i\|\--interactive**} \[*SCRIPT_FILE* \[arg1 ...\]\]
+**rpmlua** \[**--opts=OPTSTRING**\] *SCRIPT_FILE* \[arg1 ...\]
+**rpmlua** {**-e\|\--execute**} "**STATEMENT**" \[arg1 ...\]
+
+DESCRIPTION
+===========
+
+Run RPM internal Lua interpreter.
+
+**-i\|\--interactive**
+
+: Run an interactive session after executing optional script or statement.
+
+**--opts=OPTSTRING**
+
+: Perform getopt(3) option processing on the passed arguments according
+  to OPTSTRING.
+
+**-e\|\--execute**
+
+: Execute a Lua statement.
+
+EXAMPLES
+========
+
+Execute test.lua script file:
+
+> rpmlua test.lua
+
+Execute args.lua script file with option processing:
+
+> rpmlua --opts=ab:c args.lua -- 1 2 3 -c -b5
+
+Execute single statement to compare rpm versions:
+
+> rpmlua -e "print(rpm.ver('1.0') < rpm.ver('2.0'))"
+
+Run an interactive session:
+
+> rpmlua -i
+
+SEE ALSO
+========
+
+    lua(1)
+    popt(3),
+    getopt(3),
+    rpm(8),
+
+
+**http://www.rpm.org/ \<URL:http://www.rpm.org/\>**
+
+AUTHORS
+=======
+
+    Panu Matilainen <pmatilai@redhat.com>