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Remove a line from a file using sed (useful for updating known SSH server keys when they change)
For example, to remove line 5 from foo, type: vi +5d +wq foo

GZip all files in a directory separately

Split huge file into DVD+R size chunks for burning
Real DVD+R size is 4700372992 bytes, but I round down a little to be safe. To reconstitute use cat. "cat file.img.gz.aa file.img.gz.ab ..... > file.img.gz"

Hits per hour apache log

Change display resolution
-s must be a valid resolution. You can get a list of valid (and supported) resolutions via `xrandr`.

Count opening and closing braces in a string.
This function counts the opening and closing braces in a string. This is useful if you have eg long boolean expressions with many braces and you simply want to check if you didn't forget to close one.

Generate SHA1 hash for each file in a list
List files and pass to openssl to calculate the hash for each file.

Quickly build ulimit command from current values
It is helpful to know the current limits placed on your account, and using this shortcut is a quick way to figuring out which values to change for optimization or security. Alias is: $ alias ulimith="command ulimit -a|sed 's/^.*\([a-z]\))\(.*\)$/-\1\2/;s/^/ulimit /'|tr '\n' ' ';echo" Here's the result of this command: $ ulimit -c 0 -d unlimited -e 0 -f unlimited -i 155648 -l 32 -m unlimited -n 8192 -p 8 -q 819200 -r 0 -s 10240 -t unlimited -u unlimited -v unlimited -x unlimited $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 155648 max locked memory (kbytes, -l) 32 max memory size (kbytes, -m) unlimited open files (-n) 8192 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) unlimited virtual memory (kbytes, -v) unlimited file locks (-x) unlimited

Sync MySQL Servers via secure SSH-tunnel
I wanted to keep a backup of my company database server on my local homeserver. After I found maatkit to sync databases, everything except security seemed fine. SSH takes care of that part.

Reduce PDF size


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