我想要一个bash命令，我可以管道将一列数字相加。我只是想要一个快速的一行程序，基本上是这样做的:
cat FileWithColumnOfNumbers.txt | sum
当前回答
while read -r num; do ((sum += num)); done < inputfile; echo $sum
其他回答
[ghostdog74s评论的后续]
bash-2.03$ uname -sr
SunOS 5.8
bash-2.03$ perl -le 'print for 1..49999998' > infile
bash-2.03$ wc -l infile
49999998 infile
bash-2.03$ time paste -sd+ infile | bc
bundling space exceeded on line 1, teletype
Broken Pipe
real 0m0.062s
user 0m0.010s
sys 0m0.010s
bash-2.03$ time nawk '{s+=$1}END{print s}' infile
1249999925000001
real 2m0.042s
user 1m59.220s
sys 0m0.590s
bash-2.03$ time /usr/xpg4/bin/awk '{s+=$1}END{print s}' infile
1249999925000001
real 2m27.260s
user 2m26.230s
sys 0m0.660s
bash-2.03$ time perl -nle'
$s += $_; END { print $s }
' infile
1.249999925e+15
real 1m34.663s
user 1m33.710s
sys 0m0.650s
两行算吗?
awk '{ sum += $1; }
END { print sum; }' "$@"
然后你就可以不用多余的'cat'了:
sum < FileWithColumnOfNumbers.txt
sum FileWithColumnOfNumbers.txt
FWIW:在MacOS X上，你可以用一行程序完成:
awk '{ sum += $1; } END { print sum; }' "$@"
[root@pentest3r ~]# (find / -xdev -size +1024M) | (while read a ; do aa=$(du -sh $a | cut -d "." -f1 ); o=$(( $o+$aa )); done; echo "$o";)
你可以用计算器。假设使用#s的文件名为“n”:
$ cat n
1
2
3
$ (cat n | tr "\012" "+" ; echo "0") | bc
6
tr将所有换行符更改为“+”;然后在最后一个加号后面加上0，然后将表达式(1+2+3+0)输往计算器
或者，如果你可以使用awk或perl，下面是perl的一行代码:
$perl -nle '$sum += $_ } END { print $sum' n
6
如果你安装了ruby
cat FileWithColumnOfNumbers.txt | xargs ruby -e "puts ARGV.map(&:to_i).inject(&:+)"
