split and merge file

Mac:

split -b X filname outputfilename   //X is size, 10k or 100m

cat filename.01 filename.02 ... filename.20 > filename

 

Windows:

Copy 002.jpg/b + 001.txt/a 003.jpg  //b mean binary, a mean ASCII

Copy /b file1+file2 outputfile

//to split file, use winrar