true – do nothing, successfully. false – do nothing, unsuccessfully

GNU command $true $echo $? 0 $false $echo $? 1 $ Explanation true – do nothing, successfully exit with a status code indicating success. false – do nothing, unsuccessfully exit with a status code indicating failure. Related Source Code Exposition int main (int argc, char **argv) { if (argc == 2) { initialize_main (&argc, &argv); …

true and false

A UNIX Command $true $echo $? 0 $false $echo $? 1 $ UNIX Explanation true – do nothing, successfully exit with a status code indicating success. false – do nothing, unsuccessfully exit with a status code indicating failure. Related Source Code Exposition int main (int argc, char **argv) { if (argc == 2) { initialize_main …

setterm – set terminal attributes

GNU Command $setterm setterm: Argument error. Usage: setterm [options] Options: -term -reset -initialize -cursor -repeat -appcursorkeys -linewrap -default -foreground -background -ulcolor -ulcolor -hbcolor -hbcolor -inversescreen -bold -half-bright -blink -reverse -underline -store > -clear -tabs (tabn = 1-160) -clrtabs (tabn = 1-160) -regtabs -blank -dump -append -file dumpfilename -msg -msglevel -powersave -powerdown -blength -bfreq freqnumber -version …

pstree – display a tree of processes

ABOUT pstree pstree shows running processes as a tree. The tree is rooted at either pid or init if pid is omitted. If a user name is specified, all process trees rooted at processes owned by that user are shown. [bash] $pstree -A init-+-NetworkManager—3*[{NetworkManager}] |-accounts-daemon—2*[{accounts-daemon}] |-acpid |-at-spi-bus-laun-+-dbus-daemon | `-3*[{at-spi-bus-laun}] |-at-spi2-registr—{at-spi2-registr} |-atd |-avahi-daemon—avahi-daemon |-bluetoothd |-colord—2*[{colord}] |-console-kit-dae—64*[{console-kit-dae}] …

pstree – process status tree

Linux Command systemd-+-ModemManager—3*[{ModemManager}] |-NetworkManager—3*[{NetworkManager}] |-accounts-daemon—3*[{accounts-daemon}] |-avahi-daemon—avahi-daemon |-bluetoothd |-colord—3*[{colord}] |-cron |-cups-browsed—3*[{cups-browsed}] |-cupsd |-dbus-daemon |-exim4 |-fwupd—5*[{fwupd}] |-gdm3-+-gdm-session-wor-+-gdm-x-session-+-Xorg—13*[{Xorg}] | | | |-gnome-session-b-+-ssh-agent | | | | `-4*[{gnome-session-b}] | | | `-3*[{gdm-x-session}] | | `-3*[{gdm-session-wor}] | `-3*[{gdm3}] |-geoclue—3*[{geoclue}] |-gpm |-nm-dispatcher—4*[{nm-dispatcher}] |-polkitd—3*[{polkitd}] |-power-profiles—-3*[{power-profiles-}] |-rsyslogd—3*[{rsyslogd}] |-rtkit-daemon—2*[{rtkit-daemon}] |-sshd |-switcheroo-cont—3*[{switcheroo-cont}] |-systemd-+-(sd-pam) | |-at-spi-bus-laun-+-dbus-daemon | | `-4*[{at-spi-bus-laun}] | |-at-spi2-registr—3*[{at-spi2-registr}] | |-dbus-daemon | |-dconf-service—3*[{dconf-service}] | …