From 290290fcc2d092c33b6479a59ebc147ff5d60ffa Mon Sep 17 00:00:00 2001 From: Nic Boet Date: Fri, 16 Oct 2026 18:04:55 -0500 Subject: [PATCH 1/2] cmake: check for consolechars and setfont The -l option is only compiled in when HAVE_CONSOLECHARS or HAVE_SETFONT is defined; otherwise it always dies with "Unable to use both setfont and consolechars". configure.ac checks for both programs, but the CMake build never did, so -l could never work in CMake builds. Add the same checks to CMakeLists.txt, preferring consolechars as configure.ac does. Co-Authored-By: Claude Opus 5.5 --- CMakeLists.txt | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/CMakeLists.txt b/CMakeLists.txt index fba6fed..3340965 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -51,6 +51,18 @@ if (HAVE_GETOPT_H) add_definitions(-DHAVE_GETOPT_H) endif () +# -l switches the Linux console to the matrix font with consolechars or +# setfont, and is only compiled in when one of them was found; otherwise it +# always fails with "Unable to use both setfont and consolechars". +# configure.ac has always checked for them, the CMake build did not. +find_program(CONSOLECHARS consolechars) +find_program(SETFONT setfont) +if (CONSOLECHARS) + add_definitions(-DHAVE_CONSOLECHARS) +elseif (SETFONT) + add_definitions(-DHAVE_SETFONT) +endif() + Set(CURSES_NEED_NCURSES TRUE) Set(CURSES_NEED_WIDE TRUE) find_package(Curses) -- 2.55.0 From b6ae8c5c1c1afd6d5fbce5c12418a8fefe80cef1 Mon Sep 17 00:00:00 2001 From: Nic Boet Date: Fri, 16 Oct 2026 18:12:40 -0500 Subject: [PATCH 2/2] Explain that -l needs a Linux virtual console In a terminal window, cmatrix -l printed setfont's "Couldn't get a file descriptor referring to the console" followed by advice to check that setfont is in $PATH, which it is. On Linux, check with KDGKBTYPE that stdin is a virtual console before starting curses, and say so if it is not. Other platforms are unchanged. Co-Authored-By: Claude Opus 5.5 --- cmatrix.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/cmatrix.c b/cmatrix.c index 7d8ca39..076f04a 100644 --- a/cmatrix.c +++ b/cmatrix.c @@ -61,6 +61,10 @@ #include #endif +#ifdef __linux__ +#include +#endif + #ifdef HAVE_UNISTD_H #include #endif @@ -431,6 +435,20 @@ int main(int argc, char *argv[]) { } } +#if defined(__linux__) && defined(KDGKBTYPE) + /* setfont and consolechars only work on a Linux virtual console. In a + terminal window they fail with a message that says nothing useful. */ + if (console) { + char kbtype; + if (ioctl(STDIN_FILENO, KDGKBTYPE, &kbtype) != 0) { + fprintf(stderr, "cmatrix: error: -l only works on a Linux virtual " + "console (e.g. Ctrl+Alt+F2),\nnot in a terminal window. " + "Run cmatrix without -l there.\n"); + exit(EXIT_FAILURE); + } + } +#endif + /* Clear TERM variable on Windows */ #ifdef _WIN32 _putenv_s("TERM", ""); -- 2.55.0