/proc file system

Useful /proc information

Discover the possibilities of the /proc directory (https://www.linux.com/news/discover-possibilities-proc-directory)

The Linux /proc Filesystem as a Programmers’ Tool (http://www.linuxjournal.com/article/8381)

https://www.kernel.org/doc/Documentation/filesystems/proc.txt

Linux System Configuration and the proc filesystem
http://www.comptechdoc.org/os/linux/howlinuxworks/linux_hlproc.html

https://unix.stackexchange.com/questions/43539/what-do-the-flags-in-proc-cpuinfo-mean/219674#219674

/proc/sys/
     /kernel
     /vm
     /net
     /user

/proc/meminfo - Shows general memory information

/proc/iomem - Shows memory maps rages (with addresses)

/proc/<PID>/cmdline - launched command

/proc/<PID>/fd - Directory with file descriptors with pointer to file:

0 -> /dev/null
1 -> pipe:[58370]
10 -> /opt/vivaldi/vivaldi_200_percent.pak
11 -> /opt/vivaldi/locales/en-US.pak
12 -> /opt/vivaldi/resources.pak
13 -> socket:[1883069]
14 -> /dev/urandom

/proc/<PID>/net - Directory with network information

/proc/<PID>/map_files - Directory with mapped files

55dd933e3000-55dd99ecc000 -> /opt/vivaldi/vivaldi-bin
55dd99ecc000-55dd9a3cd000 -> /opt/vivaldi/vivaldi-bin
55dd9a3cd000-55dd9a3e7000 -> /opt/vivaldi/vivaldi-bin
7f72bc03b000-7f72bc058000 -> /usr/share/fonts/truetype/msttcorefonts/Webdings.ttf
7f72bc058000-7f72bc09c000 -> /usr/share/fonts/truetype/msttcorefonts/Arial.ttf
7f72bc199000-7f72bc1ea000 -> /usr/share/fonts/truetype/msttcorefonts/Times_New_Roman.ttf
7f72bccb9000-7f72bceb9000 -> /dev/shm/.com.vivaldi.Vivaldi.jajv79 (deleted)
7f72c2ec5000-7f72c3fa8000 -> /usr/lib/adobe-flashplugin/libpepflashplayer.so

/proc/<PID>/limists - Shows process limits
/proc/<PID>/environ
/proc/<PID>/cwd
/proc/<PID>/maps
/proc/<PID>/stat
/proc/<PID>/stack