Recipe: Splitting files and data

split
=====
$ mkdir split
$ cd  split

$ dd if=/dev/zero bs=100k count=1 of=data.file
1+0 records in
1+0 records out
102400 bytes (102 kB) copied, 0.00056334 s, 182 MB/s

$ split -b 10k data.file
$ ls
data.file  xaa  xab  xac  xad  xae  xaf  xag  xah  xai  xaj

$ split -b 10k data.file -d  -a 4
# Instead of k (kilobyte) suffix we can use M for MB, G for GB, c for byte, w for word etc.

$ split -l 10 data.file 
# Splits into files of 10 lines each.

csplit
======
$ cd server
$ cat server.log
SERVER-1 
[connection] 192.168.0.1 success 
[connection] 192.168.0.2 failed 
[disconnect] 192.168.0.3 pending 
[connection] 192.168.0.4 success 
SERVER-2 
[connection] 192.168.0.1 failed 
[connection] 192.168.0.2 failed 
[disconnect] 192.168.0.3 success 
[connection] 192.168.0.4 failed 
SERVER-3 
[connection] 192.168.0.1 pending 
[connection] 192.168.0.2 pending 
[disconnect] 192.168.0.3 pending 
[connection] 192.168.0.4 failed


$ csplit server.log /SERVER/ -n 2 -s {*}  -f server -b "%02d.log"  ; rm server00.log rm



String slicing
==============

$ file_jpg="name.jpg"
$ file_name=${file_jpg%.jpg}
#Means: remove wildcard appears after % from right side ( 

$ extension=${file_jpg#*.}
#  Means: show only wildcard appears from # from leftmost