Author Archives: jeffrin
groups
Package: coreutils This package contains the basic file, shell and text manipulation utilities which are expected to exist on every operating system.
Hacking with the “groups” GNU command
20.4 `groups’: Print group names a user is in ============================================= `groups’ prints the names of the primary and any supplementary groups for each given USERNAME, or the current process if no names are given. If more than one name is given, the name of each user is printed before the list of that user’s groups …
true and false
true . exit with a status code indicating success. false. exit with a status code indicating failure.
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 …
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); …
Continue reading “true – do nothing, successfully. false – do nothing, unsuccessfully”
dig (domain information groper )
DNS lookup utility. contained in debian package “dnsutils”.
setterm
setterm sets terminal attributes.
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 …
quote
Enclosing characters in single quotes preserves the literal value of each character within the quotes.