awk
é bom para esse tipo de saída formatada de entrada formatada:
awk -F, '{printf("line starts at %d and ends at %d with value %d\n", $1, $2, $3)}' file
line starts at 3 and ends at 3 with value 100
line starts at 4 and ends at 2 with value 50
line starts at 8 and ends at 5 with value 80