Commands using cat (508)

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Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Adding specific CustomLog for each Virtual Domain of Apache

Copy ssh keys to [email protected] to enable password-less ssh logins.
Alternative for machines without ssh-copy-id

look for a function reference in a library set

Monitor cpu in realtime.

Display the top ten running processes - sorted by memory usage
ps returns all running processes which are then sorted by the 4th field in numerical order and the top 10 are sent to STDOUT.

Print Memory Utilization Percentage For a specific process and it's children
Change the name of the process and what is echoed to suit your needs. The brackets around the h in the grep statement cause grep to skip over "grep httpd", it is the equivalent of grep -v grep although more elegant.

Analyze awk fields
translate and number lines is simpler and you use tr to choose your delimiter (eg for csv files)

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.


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