|^^|
http://www.kossboss.com/linux---bytes-to-human-readable-command
http://www.kossboss.com/linuxbegginer_timestamp
BASH/SCRIPT EXAMPLE TO ADD TIME STAMP TO FILE
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Try this Command - 2 ways - sometimes better to use commands full name just incase another exists somewhere:
# date --help
(or)
# /bin/date --help
TRY THESE COMMANDS LIKE THIS SO YOU SEE WHY ITS SO LONG IN THE END:
# date +%s
1362732681 - time since unix epoch (1970-01-01 UTC) - its a universal time we can all measure from
# date +%T
00:52:35
# date +%D
03/08/13
# date +s%s
s1362732770 <-- would do as a good timestamp even without the "s" in the front
# date +s%s-D%D
s1362732786-D03/08/13
# date +s%s-D%D-T%T-%S
s1362732791-D03/08/13-T00:53:11-11
# date +s%s-D%D-T%T-%S | tr "/" "_"
s1362732796-D03_08_13-T00:53:16-16
# date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"
s1362732801-D03_08_13-T00_53_21-21 <-- Good long timestamp
WE CAN PREFIX IT WITH /bin JUST TO BE SAFE
# date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"
(or)
# /bin/date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"
SO PUT THAT INTO A VARIABLE - those ` are backticks they make commands inside em run then you can use the text as the variable (or part of the variable):
# DATEnow=`/bin/date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"`
VERIFY - LOTS OF WAYS TO CALL VARIABLE:
# echo $DATEnow
SET ANOTHER VARIABLE WITH IT:
# FILENAME=/tmp/somefile-${DATEnow}
(or)
# FILENAME=/tmp/somefile-$DATEnow
(or without using DATEnow)
# FILENAME=/tmp/somefile-`/bin/date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"`
Type "echo $FILENAME" to confirm at anytime.
NOW YOU CAN USE FILENAME AS VARIABLE IN ANY FUNCTION LIKE MAYBE A COPY SCRIPT:
REMEMBER EACH SCRIPT STARTS WITH A SHABANG(#!/bin/bash) TELLS LINUX WHICH INTERPRETER TO USE FOR THE SCRIPT- ITS A COMMENT SO IT DOESNT AFFECT THE CODE - JUST WHO RUNS THE CODE
# cd /tmp
# touch script.sh
# chmod 777 script.sh
(or WE JUST NEED EXECUTION BIT ON IT TO RUN [without execution bit you can still run script in bash like so "source scriptfilename")
nano is a simple file editor - i dont like it but its simple so its good for beginners - i just think beginners should start with vi though to get better at linux typing
# nano script.sh
(or my personal favorite vi)
# chmod +x script.sh
When you start vi you start in normal mode - you cant type just yet. Then key the letter "i" to start TYPING - insert mode. When done use "ESC" key to get get out of insert mode. When out of insert mode your in normal mode - just as when you entered vi - to SAVE Type the following ":w" Without the quotes (SHIFT+; to get the : and then key the letter w and then hit enter) - to SAVE AND EXIT ":wq!" - to EXIT AND NOT SAVE ":q!" - note the ! forces the commands without it you would be fine too, google "how to use vi" also google "how to install vim" and then use vim instead of vi - its just like vi but with more features - vi is just on every system so thats why I talk about it here
# vi script.sh
PUT THE FOLLOWING IN YOUR SCRIPT (when done can execute script like this "./script.sh" when in tmp folder - if out of tmp folder do "./tmp/script.sh" - both without quotes -- also make sure that you dont put # anywhere besides the shebang - it actually doesnt hurt at all to put # its just a comment line thus it will ignore commands so thats why Im not including it with the actual commands):
#!/bin/bash
DATEnow=`/bin/date +s%s-D%D-T%T-%S | tr "/" "_" | tr ":" "_"`
SOURCEFILE=/tmp/somefile
DESTINATIONFILE=/tmp/somefolder/newfile-${DATEnow}
echo "THE FOLLOWING COMMAND JUST RAN: " cp "$SOURCEFILE" "$DESTINATIONFILE"
cp "$SOURCEFILE" "$DESTINATIONFILE"
EOF