Closes #733

Closes #730

A signal interrupts the blocking function calls in the main iteration, so
there is really no need to do (unsafe) heavy lifting in the signal handler.

Closes #705

a1346054 authored Sep 12, 2022 and derf committed Feb 15, 2023

No need to use `grep -F` here

orbea authored Oct 16, 2022 and derf committed Jan 22, 2023

These are no longer supported in upcoming clang versions.

warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]

Reference: https://archives.gentoo.org/gentoo-dev/message/dd9f2d3082b8b6f8dfbccb0639e6e240

Anthony Iliopoulos authored Aug 22, 2022 and derf committed Aug 22, 2022

inotify_add_watch calls fail when the file is a url, since it does not
correspond to an actual on-disk path. The temporary file path fetched by
curl could be kept and monitored, but since this is unlikely to change
just avoid monitoring files opened via a url.

Closes #665

The default user agent is empty, which is not that friendly.
Closes #660

Closes #656

use libmagic to detect valid file formats

init_parse_options calls feh_prepare_filelist, which in turn calls
feh_file_info_preload if opt.preload is set. This function will load all
images in the filelist to determine their attributes, so we need to initialize
libmagic before calling init_parse_options.

Add a global `magic_t magic` and initialize it just once.

Also `feh_is_image()` now calls itself to check compressed files, saving
some duplicate code.

Writing our own magic bytes detection is prone to errors and an
everlasting catch-up-game. Let's use libmagic to get things right,
this is less code and makes things more reliable.

Building without libmagic is still possible. That will make the code
act like specifying FEH_SKIP_MAGIC=1, effectively passing everything
to imlib2.

When _POSIX_C_SOURCE is defined, macOS hides the definitions of mkdtemp
and mkstemps, among others. Define _DARWIN_C_SOURCE to counteract that.

Guilherme Janczak authored Jan 11, 2022 and derf committed Jan 16, 2022

getopt_long() is widely supported these days, removing it from the
source tree should be okay.

Here's documentation or the implementation of getopt_long on many
systems:

All the BSDs:
https://man.netbsd.org/NetBSD-9.2-STABLE/getopt_long.3
https://man.openbsd.org/OpenBSD-7.0/getopt_long
https://www.freebsd.org/cgi/man.cgi?query=getopt_long
https://leaf.dragonflybsd.org/cgi/web-man?command=getopt_long

Illumos (OpenSolaris fork):
https://illumos.org/man/3c/getopt_long

The musl, newlib, and uclibc-ng libcs:
https://gogs.waldemar-brodkorb.de/oss/uclibc-ng/src/master/libc/unistd/getopt_long-simple.c#L49-L52
https://git.musl-libc.org/cgit/musl/tree/src/misc/getopt_long.c#n140
https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=newlib/libc/stdlib/getopt.c;h=d4f225a7a735dc741d2874eb6c131b6fce2967c5;hb=HEAD#l475

Mingw-w64:
https://github.com/mirror/mingw-w64/blob/master/mingw-w64-crt/misc/getopt.c#L542-L549

Mac OS X:
https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/getopt_long.3.html

Closes #642