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Back up /etc directory with a name based on the current date and the hostname of the machine, then chown the file for the current user for use.
On the Mac, the 'ls' function can sort based on month/day/time, but seems to lack ability to filter on the Year field (#9 among the long listed fields). The sorted list continuously increases the 'START' year for the most recently accessed set of files. The final month printed will be the highest month that appeared in that START year. The command does its magic on the current directory, and suitably discards all entries that are themselves directories. If you expect files dating prior to 2002, change the START year accordingly.
On CentOS at least, date returns a boolean for the common date string formats, including YYYY-MM-DD. In the sample output, you can see various invalid dates returning 0 whereas a simple regex check would return 1 for the invalid dates.
-d, --date=STRING display time described by STRING, not `now'
The version of date on OS X does not appear to have this same option.
Format of the response: [-]HH:mm
Appends the input file with the date format YYYY-MM-DD.bak. Also runs silently if you remove the -v on the cp at the end of the function.
Fake system time before running any command.
Choosing your year and month. You only need the gnu date command and bash. desiredDay of the week is (1..7); 1 is Monday.
If you want desiredDay of week (0..6); 0 is Sunday
desiredDay=6; year=2012; month=5; n=0; while [ $(date -d "$year-$((month+1))-1 - $n day" "+%w") -ne $desiredDay ]; do n=$((n+1)); done; date -d "$year-$((month+1))-1 - $n day" "+%x"
If your locale has Monday as the first day of the week, like mine in the UK, change the two $7 into $6
This is a little trickier than finding the last Sunday, because you know the last Sunday is in the first position of the last line. The trick is to use the NF less than or equal to 7 so it picks up all the lines then grep out any empty lines.
The command renames all files in a certain directory. Renaming them to their date of creation using EXIF. If you're working with JPG that contains EXIF data (ie. from digital camera), then you can use following to get the creation date instead of stat.
* Since not every file has exif data, we want to check that dst is valid before doing the rest of commands.
* The output from exif has a space, which is a PITA for filenames. Use sed to replace with '-'.
* Note that I use 'echo' before the mv to test out my scripts. When you're confident that it's doing the right thing, then you can remove the 'echo'... you don't want to end up like the guy that got all the files blown away.
Get the time since epoch. Useful when working with commands and logs which use this format.
Gets any date since today. Other examples of recognized expressions are "2 years 4 days ago", "7 months" (in the future), "next Sunday", "yesterday", "tomorrow", etc.
Convert readable date/time with `date` command
date -ud @1320198157
uses the -u switch for UTC
Another way could be
echo $(($(date -ud "00:29:36" +%s)%86400))
The same with colors