私はあなたが使うべきだと信じています：bc
例えば：
echo "scale = 10; 123.456789/345.345345" | bc
（これはUNIXの方法です。各ツールは本来の機能をうまく実行することに特化しており、すべてが連携して優れた機能を実行します。優れたツールを他のツールとエミュレートしないで、連携させてください。）
出力：
.3574879198
1またはの代わりにのスケールで10：
echo "scale = 1; 123.456789/345.345345" | bc
出力：
.3
これは丸めを実行しないことに注意してください。
より複雑な操作を行う必要がある場合はawkに、最も複雑な操作を行う場合はperlに切り替えることを強くお勧めします。
例：awkで実行された操作：
# create the test file:
printf '1.5493482,3.49384,33.284732,23.043852,2.2384,12.1,13.4,...\n' > somefile
printf '3.384,3.282342,23.043852,2.23284,8.39283,14.1,15.2,...\n' >> somefile
# do OP's calculations (and DEBUG print them out!)
awk -F',' '
# put no single quote in here... even in comments! you can instead print a: \047
# the -F tell awk to use "," as a separator. Thus awk will automatically split lines for us using it.
# $1=before first "," $2=between 1st and 2nd "," ... etc.
function some_awk_function_here_if_you_want() { # optionnal function definition
# some actions here. you can even have arguments to the function, etc.
print "DEBUG: no action defined in some_awk_function_here_if_you_want yet ..."
}
BEGIN { rem="Optionnal START section. here you can put initialisations, that happens before the FIRST file-s FIRST line is read"
}
(NF>=8) { rem="for each line with at least 8 values separated by commas (and only for lines meeting that condition)"
calc1=($2 - $7)
calc2=($3 * $2)
calc3=($2 - $1)
calc4=($2 + $8)
# uncomment to call this function :(ex1): # some_awk_function_here_if_you_want
# uncomment to call this script:(ex2): # cmd="/path/to/some/script.sh \"" calc1 "\" \"" calc2 "\" ..." ; rem="continued next line"
# uncomment to call this script:(ex2): # system(cmd); close(cmd)
line_no=(FNR-1) # ? why -1? . FNR=line number in the CURRENT file. NR=line number since the beginning (NR>FNR after the first file ...)
print "DEBUG: calc1=" calc1 " , calc2=" calc2 " , calc3=" calc3 " , calc4=" calc4 " , line_no=" line_no
print "DEBUG fancier_exemples: see man printf for lots of info on formatting (%...f for floats, %...d for integer, %...s for strings, etc)"
printf("DEBUG: calc1=%d , calc2=%10.2f , calc3=%s , calc4=%d , line_no=%d\n",calc1, calc2, calc3, calc4, line_no)
}
END { rem="Optionnal END section. here you can put things that need to happen AFTER the LAST file-s LAST line is read"
}
' somefile # end of the awk script, and the list of file(s) to be read by it.