I will explain how to install libgif-dev. Install libgif-dev using the apt command. Run with administrator privileges using sudo.
sudo apt install -y libgif-dev
When you install libgif-dev, "libgif7" is also installed. "Libgif7" seems to mean version 7 of "libgif".
What is libgif-dev
(The following description is unconfirmed as of May 14, 2020)
libgif-dev is one of the libraries for reading, writing and editing GIF images.
Required to read "gif_lib.h" in a C source file.
In Perl, there are modules that use "gif_lib.h" to read and write GIF images. An example is Imager::File::GIF, Imager's GIF image read / write module.
In order to install Imager::File::GIF, "gif_lib.h" is installed in the header file loading path, and the corresponding shared library "libgif.so" is installed in the library loading path. is needed.
Installing libgif-dev installs the "gif_lib.h" header and its corresponding shared library.
On the Web, PNG, GIF, and JPEG images are often uploaded, so install the GIF library.
Please refer to the following for the reading path of the header file and the reading path of the library.