merge sam files by "cat"

tail -n +29 7550X2_1.sam > 1.sam

tail -n +29 7550X2_2.sam > 2.sam

tail -n +29 7550X2_3.sam > 3.sam

tail -n +29 7550X2_4.sam > 4.sam

tail -n +29 7550X2_5.sam > 5.sam

head -n 28 1.sam > header.txt

cat header.txt 1.sam 2.sam 3.sam 4.sam 5.sam > hello.sam

picard-tools-1.42/SortSam.jar INPUT=hello.sam OUTPUT=hello.sorted.sam CREATE_INDEX=false SO=coordinate COMPRESSION_LEVEL=5 MAX_RECORDS_IN_RAM=7500000 TMP_DIR=.

picard-tools-1.42/SortSam.jar INPUT=hello.sorted.sam OUTPUT=hello.sorted.bam CREATE_INDEX=true SO=coordinate COMPRESSION_LEVEL=5 MAX_RECORDS_IN_RAM=7500000 TMP_DIR=.