terminal emulator support

README.md

@@ -32,10 +32,9 @@ _/\ __)/_)    pkgs   130
 
 - [ ] Add optional and additional information detection.
     - [ ] CPU
-    - [ ] Terminal Emulator ([#12](https://github.com/dylanaraps/pfetch/pull/12))
+    - [ ] Terminal Emulator
         - The way I implement this in `neofetch` is interesting.
-    - [x] Terminal colors ([commit](https://github.com/dylanaraps/pfetch/commit/ba03cb3cf4dfbc767abce6acd53c07ab5568e23d))
-    - [ ] Window manager ([#13](https://github.com/dylanaraps/pfetch/pull/13))
+    - [ ] Terminal colors
     - [ ] ???
 - [ ] Expand operating system support.
     - [ ] Solaris ([#5](https://github.com/dylanaraps/pfetch/issues/5))
@@ -47,7 +46,7 @@ _/\ __)/_)    pkgs   130
         - [ ] CYGWIN
         - [ ] MSYS
         - [ ] MINGW
-        - [x] WSL (*this is fairly simple*)
+        - [ ] WSL (*this is fairly simple*)
 
 ## Configuration
 
@@ -59,7 +58,7 @@ _/\ __)/_)    pkgs   130
 # Default: first example below
 # Valid: space separated string
 #
-# OFF by default: shell palette
+# OFF by default: shell
 PF_INFO="ascii title distro host kernel uptime pkgs memory"
 
 # Example: Only ASCII.

pfetch

@@ -154,12 +154,6 @@ get_os() {
             if command -v lsb_release; then
                 distro=$(lsb_release -sd)
 
-                # lsb_release sometimes adds quotes around the output,
-                # this simply remove quotes from the start/end if they
-                # exist.
-                distro=${distro##\"}
-                distro=${distro%%\"}
-
             else
                 # Disable warning about shellcheck not being able
                 # to read '/etc/os-release'. This is fine.
@@ -171,19 +165,6 @@ get_os() {
             # don't follow any os-release/lsb standards whatsoever.
             command -v crux        && distro=$(crux)
             command -v guix        && distro='Guix System'
-
-            # Check to see if Linux is running in Windows 10 under
-            # WSL (Windows subsystem for Linux) and append a string
-            # accordingly.
-            #
-            # If the kernel version string ends in "-Microsoft",
-            # we're very likely running under Windows 10 in WSL.
-            #
-            # This also acts as a means of allowing the user to
-            # fake this by changing their kernel version to end in
-            # "Microsoft".
-            [ "${kernel%%*-Microsoft}" ] ||
-                distro="$distro on Windows 10"
         ;;
 
         Darwin*)
@@ -259,10 +240,6 @@ get_kernel() {
    esac
 }
 
-get_shell() {
-    log shell "${SHELL##*/}" >&6
-}
-
 get_host() {
     case $os in
         Linux*)
@@ -375,10 +352,6 @@ get_uptime() {
 }
 
 get_pkgs() {
-    # This is just a simple wrapper around 'command -v' to avoid
-    # spamming '>/dev/null' throughout this function.
-    has() { command -v "$1" >/dev/null; }
-
     # This works by first checking for which package managers are
     # installed and finally by printing each package manager's
     # package list with each package one per line.
@@ -399,27 +372,27 @@ get_pkgs() {
         case $os in
             Linux*)
                 # Commands which print packages one per line.
-                has kiss       && kiss l
-                has bonsai     && bonsai list
-                has pacman-key && pacman -Qq
-                has dpkg       && dpkg-query -f '.\n' -W
-                has rpm        && rpm -qa
-                has xbps-query && xbps-query -l
-                has apk        && apk info
+                command -v kiss       && kiss l
+                command -v bonsai     && bonsai list
+                command -v pacman-key && pacman -Qq
+                command -v dpkg       && dpkg-query -f '.\n' -W
+                command -v rpm        && rpm -qa
+                command -v xbps-query && xbps-query -l
+                command -v apk        && apk info
 
                 # Directories containing packages.
-                has brew       && printf '%s\n' "$(brew --cellar)/"*
-                has emerge     && printf '%s\n' /var/db/pkg/*/*/
-                has pkgtool    && printf '%s\n' /var/log/packages/*
+                command -v brew       && printf '%s\n' "$(brew --cellar)/"*
+                command -v emerge     && printf '%s\n' /var/db/pkg/*/*/
+                command -v pkgtool    && printf '%s\n' /var/log/packages/*
 
                 # GUIX requires two commands.
-                has guix       && {
+                command -v guix       && {
                     guix package -p /run/current-system/profile -I
                     guix package -I
                 }
 
                 # NIX requires two commands.
-                has nix-store  && {
+                command -v nix-store  && {
                     nix-store -q --requisites /run/current-system/sw
                     nix-store -q --requisites ~.nix-profile
                 }
@@ -427,11 +400,11 @@ get_pkgs() {
 
             Darwin*)
                 # Commands which print packages one per line.
-                has pkgin      && pkgin list
-                has port       && port installed
+                command -v pkgin      && pkgin list
+                command -v port       && port installed
 
                 # Directories containing packages.
-                has brew       && printf '%s\n' /usr/local/Cellar/*
+                command -v brew       && printf '%s\n' /usr/local/Cellar/*
             ;;
 
             FreeBSD*)
@@ -599,19 +572,128 @@ get_memory() {
     log memory "${mem_used:-?}M / ${mem_full:-?}M" >&6
 }
 
-get_palette() {
-    # Print the first 8 terminal colors. This uses the existing
-    # sequences to change text color with a sequence prepended
-    # to reverse the foreground and background colors.
+get_term() {
+    # Workaround for macOS systems that don't support the
+    # "algorithm" of obtaining the terminal program name.
     #
-    # This allows us to save hardcoding a second set of sequences
-    # for background colors.
-    palette="  $c1  $c2  $c3  $c4  $c5  $c6  $c7  "
+    # This also doubles as a means of allowing the user to
+    # set whatever value they like here through the
+    # '$TERM_PROGRAM' environment variable.
+    case $TERM_PROGRAM in
+        iTerm.app)    term=iTerm2 ;;
+        Terminal.app) term='Apple Terminal' ;;
+        Hyper)        term=HyperTerm ;;
+        *)            term=${TERM_PROGRAM%%.app} ;;
+    esac
 
-    # Print the palette with a newline before and after.
-    # The '\033[%sC' moves the text to the right, the
-    # length of the ascii art.
-    printf '\n[%sC%s\n' "${ascii_width-1}" "$palette" >&6
+    # Special case for TosWin2 (FreeMiNT) which doesn't
+    # support the "algorithm" of obtaining the terminal
+    # program name.
+    [ "$TERM" = tw52 ] || [ "$TERM" = tw100 ] &&
+        term=TosWin2
+
+    # Special case for when 'pfetch' is run over SSH.
+    [ "$SSH_CONNECTION" ] &&
+        term=$SSH_TTY
+
+    # This surprisingly reliable method of detecting the current
+    # terminal emulator is kinda neat.
+    #
+    # It works by looping through each parent of each process
+    # starting with '$PPID' (the parent process ID) until we
+    # find a match or hit PID 1 (init).
+    #
+    # On each iteration the name of the current parent process
+    # is checked against a list of good values and bad values.
+    # If no match is found we check the parent of the parent
+    # and so on.
+    #
+    # Using this method *no* terminal emulator names are
+    # hardcoded and the list remains small and general. In short
+    # it's basically a list of what *isn't* a terminal emulator
+    # and a list of places we should *stop*.
+    while [ -z "$term" ]; do
+        # This block is OS-specific and handles the fetching of
+        # the parent process (of the parent) and the fetching of
+        # said process' name.
+        case $os in
+            Linux*)
+                # On Linux some implementation of 'ps' aren't POSIX
+                # compliant, thankfully Linux provides this information
+                # though the '/proc' filesystem.
+                #
+                # This loops line by line over the '/proc/PID/status'
+                # file splitting at ':' and '<TAB>', we then look for
+                # the key containing 'PPid' and grab the value.
+                while IFS=':	' read -r key val; do
+                    case $key in
+                        PPid)
+                            ppid=$val
+                            break
+                        ;;
+                    esac
+                done < "/proc/${ppid:-$PPID}/status"
+
+                # Get the name of the parent process.
+                read -r name < "/proc/$ppid/comm"
+            ;;
+
+            Windows*)
+                # I need some assistance to add Windows support
+                # as the 'ps' command used in MINGW, MSYS and CYGWIN
+                # isn't POSIX compliant(?).
+                return
+            ;;
+
+            *)
+                # POSIX compliant 'ps' makes this really easy,
+                # just two simple commands to grab the parent
+                # process ID and the ID's name.
+                ppid=$(ps -p "${ppid:-$PPID}" -o ppid=)
+                name=$(ps -p "$ppid"          -o comm=)
+            ;;
+        esac
+
+        # Check the parent process name against a list of good and bad
+        # values. On a bad value we either keep iterating up the parent
+        # process list or we stop altogether (PID 1 for example).
+        case $name in
+            # If the parent process name matches the user's shell (or
+            # anything that looks like a shell), do another iteration.
+            #
+            # This also includes 'screen' and anything that looks like
+            # 'su' or 'sudo'.
+            ${SHELL##*/} | *sh | screen | su* ) ;;
+
+            # If the parent process name matches 'login', 'init' or
+            # '*Login*' we're most likely in the TTY and not a graphical
+            # session. In this case 'term' is set to the current TTY and
+            # we end here.
+            login* | *Login* | init)
+                term=$(tty)
+            ;;
+
+            # If the parent process name matches anything in this list
+            # we can no longer continue. We've either hit PID 1 or a parent
+            # which *won't* lead to the terminal emulator's PID.
+            ruby      | systemd  | python*  | 1  | sshd* | tmux* |\
+            USER*PID* | kdeinit* | launchd* | '' )
+                break
+            ;;
+
+            # If none of the above have matched we've reached the terminal
+            # emulator's PID and we can end here.
+            *)
+                term=${name##*/}
+            ;;
+        esac
+    done
+
+    [ "$term" ] && log term "$term" >&6
+}
+
+get_shell() {
+    log shell "${SHELL##*/}" >&6
 }
 
 get_ascii() {
@@ -1088,7 +1170,7 @@ main() {
         # Disable globbing and set the positional parameters to the
         # contents of 'PF_INFO'.
         set -f
-        set +f ${PF_INFO-ascii title os host kernel uptime pkgs memory}
+        set +f ${PF_INFO-ascii title os host kernel term uptime pkgs memory}
 
         # Iterate over the info functions to determine the lengths of the
         # "info names" for output alignment. The option names and subtitles