Console Output

How do we handle console output?

Issues

Windows Encoding

Windows uses the wrong encoding for glib output: https://gitlab.com/inkscape/inkscape/-/merge_requests/418#note_119199350

Possible solutions:

• Give up on g_log (g_message, etc.). This would be a major effort and doubtful we can do it in a time for 1.0.
• Use g_set_print_handler as described in https://stackoverflow.com/questions/43927373/force-utf-8-encoding-in-glibs-g-print
• Use g_log_set_handler as done in ui/dialog/messages.cpp
• Ask the GTK people.
  • Related glib bug: https://bugzilla.gnome.org/show_bug.cgi?id=782578
  • Bug as GitLab issue: https://gitlab.gnome.org/GNOME/glib/-/issues/1270

Fixed in glib 2.62, see https://gitlab.gnome.org/GNOME/glib/-/merge_requests/767

Glib vs iostreams

Mix of glib output functions and std::cout/std::cerr. In principle mixing the two can cause problems but in practice it does not as by default std::cout/std::cerr are synced with stdio (std::sync_with_stdio).

Current Use

• std::cout: 976
• std::cerr: 361

• printf: 439
• sprintf: 285
• fprintf: 122
• snprintf: 47

• g_print: 137
• g_printerr: 12
• g_strdup_printf: 331
• g_snprintf: 24

• g_log/g_logv: 23
• g_message: 312
• g_warning: 470
• g_critical: 47
• g_info: 72
• g_debug: 4

Message dialog

Our message dialog can intercept g_log, etc. and redirect it to the dialog. This is done through g_log_set_handler if "Capture log messages" is checked. As we intercept everything, we could just intercept stdout/stderr as a comment in the message code suggests. How do actually do this is not clear.

For std::cout only:

// Start redirection
std::stringstream ss;
std::streambuf *sb = std::cout.rdbuf(ss.rdbuf());

// End redirection
std::cout.redbuf(sb);

For everything:

char huge_string_buf[1000];
freopen("/dev/null", "a", stdout);
setbuf(stdout, huge_string_buf);

Buffer could get filled up (shouldn't overflow).