sxcs - Simple X Color Sniper

Color picker and magnifier for X11.

Usage

Button1 will select and print the color to stdout, the output is TAB separated hex, rgb, and hsl. Scroll Up/Down will zoom in and out. Any other mouse button will quit sxcs.

Output format can be chosen via cli argument. Zoom/magnification can be disabled via --mag-none.

$ sxcs --rgb --mag-none
rgb:	22 158 111

Copying the hex output to clipboard (using xclip):

$ sxcs -o --hex | cut -f 2 | xclip -in -selection clipboard

Color output can be disabled via --color-none, which more or less turns sxcs into a magnifier.

The magnifying window can be customized via using --mag-filters <filter-list>, where filter-list is a comma separated list of filters to apply. The filter-list will be applied in order, as given by the user.

The default filter list is the following:

$ sxcs --mag-filters "grid,circle,xhair"

Following are a couple more examples:

$ sxcs --mag-filters "square,xhair"

$ sxcs --mag-filters "grid,xhair"

Consult the manpage to see a list of all available cli arguments and filters:

$ man sxcs

Dependencies

• Build Dependencies:

  • C89 compiler
  • necessary headers

• Runtime Dependencies:

  • Xlib
  • Xcursor
  • POSIX 2001 C standard library

Building

• Simple build:

$ cc -o sxcs sxcs.c -s -l X11 -l Xcursor

• Recommended optimized build:

$ gcc -o sxcs sxcs.c -Ofast -march=native -fwhole-program -fno-plt \
    -fno-semantic-interposition -fgraphite-identity -floop-nest-optimize \
    -fipa-pta -fno-asynchronous-unwind-tables -fno-ident -fno-pie \
    -s -no-pie -l X11 -l Xcursor

• Recommended debug build:

$ gcc -o sxcs sxcs.c -std=c89 -Wall -Wextra -Wpedantic \
    -g3 -D DEBUG -O0 -fsanitize=address,undefined -l X11 -l Xcursor

• Optionally run some static analysis:

$ make -f analyze.mk

Installing

Just copy the executable and the man-page to the appropriate location:

$ sudo cp sxcs /usr/local/bin
$ sudo cp sxcs.1 /usr/local/share/man/man1

Or using the install utility:

$ sudo install -Dm755 sxcs /usr/local/bin/sxcs
$ sudo install -Dm644 sxcs.1 /usr/local/share/man/man1/sxcs.1

Limitation

Cursor size bigger than 255x255 causes visual glitches, it seems to be a X11/Xcursor limitation.

One alternative would be using XComposite and using an override_redirect window. Which is what was being done (incorrectly) before commit 33490dd. I suspect doing this correctly would require way too much code, probably above my self imposed limit of ~800 SLoC for this project.

TODOs

grep the source to find TODOs:

$ grep -Hn -E 'TODO|FIXME' sxcs.c