BEAUTY AND PLAY
ABOUT until until command in Linux used to execute a set of commands as long as the final command in the ‘until’ Commands has an exit status which is not zero. It is mostly used where the user needs to execute a set of commands until a condition is true. A TYPICAL SHELL EXPOSURE [bash] …
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ABOUT times Print the accumulated user and system times for the shell and for processes run from the shell [bash] $times 0m0.063s 0m0.024s 0m0.008s 0m0.012s $times pin 0m0.064s 0m0.025s 0m0.008s 0m0.012s $times ping 0m0.065s 0m0.025s 0m0.008s 0m0.012s $times –help times: times Display process times. Prints the accumulated user and system times for the shell and …
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ABOUT test test provides no output, but returns 0 for “true” (test successful) and 1 for “false” (test failed). RELATED COMMAND LINE EXPOSURE [bash] $num=10; if (test $num -gt 5); then echo "yes"; else echo "no"; fi yes $num=1; if (test $num -gt 5); then echo "yes"; else echo "no"; fi no $num=5; if (test …
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ABOUT suspend Suspend the execution of this shell until it receives a SIGCONT signal. [bash] $suspend ^C^C |^Z [/bash] [bash] $kill -18 5139 $ [/bash] [bash] $suspend ^C^C |^Z $ [/bash] LINK https://ss64.com/bash/suspend.html
ABOUT shift shift [n] The positional parameters from n+1 … are renamed to $1 …. Parameters represented by the numbers $# down to $#-n+1 are unset. n must be a non-negative number less than or equal to $#. If n is 0, no parameters are changed. If n is not given, it is assumed to …
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ABOUT return Causes a function to stop executing and return the value specified by n to its caller. If n is omitted, the return status is that of the last command executed in the function body. TYPICAL COMMAND LINE EXPOSURE [bash] $cat learn function e() { echo hello echo "10" } e value=e #echo $value …
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ABOUT readonly Marks name specified by Name parameter as read-only. TYPICAL COMMANDLINE SESSION [bash] $a=1 $a=2 $echo $a 2 $readonly a $a=1 bash: a: readonly variable $echo $a 2 $a=2 bash: a: readonly variable $ [/bash] LINK https://www.ibm.com/support/knowledgecenter/ssw_aix_72/com.ibm.aix.osdevice/bourne_shell_builtin_cmd_list.htm
ABOUT eval eval is a builtin command of the Bash shell. It concatenates its arguments into a single string, joining the arguments with spaces, then executes that string as a bash command. It’s similar to running bash -c “string”, but eval executes the command in the current shell environment rather than creating a child shell …
[bash light=”true”] $command $echo $? 0 $enable -n command $command bash: command: command not found $echo $? 127 $enable command $command $enable -n enable $enable bash: enable: command not found $ [/bash] RELATED SOURCE CODE EXPOSURE [c light=”true”] /* Enable/disable shell commands present in LIST. If list is not specified, then print out a list …
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[bash light=”true”] $dbus-monitor –session –profile | tee dbus-monitor-profile.txt #type timestamp serial sender destination path interface member # in_reply_to sig 1542567372.723960 2 org.freedesktop.DBus :1.3693 /org/freedesktop/DBus org.freedesktop.DBus NameAcquired sig 1542567372.723980 4 org.freedesktop.DBus :1.3693 /org/freedesktop/DBus org.freedesktop.DBus NameLost sig 1542567373.088315 5 org.freedesktop.DBus :1.3692 /org/freedesktop/DBus org.freedesktop.DBus NameLost sig 1542567373.088350 3737 org.freedesktop.DBus <none> /org/freedesktop/DBus org.freedesktop.DBus NameOwnerChanged sig 1542567373.088364 6 org.freedesktop.DBus :1.3692 …
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