Check These Out
Unlike other methods that use pipes and exec software like tr or sed or subshells, this is an extremely fast way to print a line and will always be able to detect the terminal width or else defaults to 80. It uses bash builtins for printf and echo and works with printf that supports the non-POSIX `-v` option to store result to var instead of printing to stdout.
Here it is in a function that lets you change the line character to use and the length with args, it also supports color escape sequences with the echo -e option.
$ function L() { local l=; builtin printf -vl "%${2:-${COLUMNS:-`tput cols 2>&-||echo 80`}}s\n" && echo -e "${l// /${1:-=}}"; }
With color:
$ L "`tput setaf 3`="
1. Use printf to store n space chars followed by a newline to an environment variable "l" where n is local environment variable from $COLUMNS if set, else it will use `tput cols` and if that fails it will default to 80.
2. If printf succeeds then echo `$l` that contains the chars, replacing all blank spaces with "-" (can be changed to anything you want).
From: http://www.askapache.com/linux/bash_profile-functions-advanced-shell.html http://www.askapache.com/linux/bash-power-prompt.html
Possible use, to filter something in stderr:
(/usr/bin/$COMMAND $PARAM 3>&1 1>&2 2>&3 | grep -v $uninteresting_error ) 3>&1 1>&2 2>&3
Works also with SML/NJ and other interpreters or tools with interactive environments.
Replace 'csv_file.csv' with your filename.
Yet another way to add a line at the top a of text file with the help of the tac command (reverse cat).
GoAccess is an open source real-time Apache web log analyzer and interactive viewer that runs in a terminal in *nix systems. It provides fast and valuable HTTP statistics for system administrators that require a visual server report on the fly. http://goaccess.prosoftcorp.com/
Useful to determine the source_ip of outgoing packages to a certain destination
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"
}
This will lower the quality of mp3 files, but is necessary to play them on some mobile devices.