Code:
# cat aaa
aabbccddDDCCDDCCaabbcc 123
CCaaCCBBCCaaaaaaaCCCaa 234
CCDDCCAACCCCccccccccaa 999
# for i in `cut -f1 aaa -d ' '`; do echo -n "$i "; echo -n $i | sed 's/[^a-z]//g' | wc -c; done
aabbccddDDCCDDCCaabbcc 14
CCaaCCBBCCaaaaaaaCCCaa 11
CCDDCCAACCCCccccccccaa 10
