我发现自己会用jq来做这样的事情，即使不使用JSON:

$ echo -e '1\n2\n3' | jq --slurp add
6

它已经成为我最近编写的几乎每个脚本的标准依赖项。

粘贴不是必需的。只要files.txt包含一个或多个有效文件名，就可以执行以下操作:

<files.txt xargs stat -c %s | paste -sd+ | bc

如果没有文件，Cat不需要插入0。如果没有管道，也许在脚本中更方便，您可以使用:

(xargs -a files.txt stat -c %s || echo 0) | paste -sd+ | bc

#
#       @(#) addup.sh 1.0 90/07/19
#
#       Copyright (C) <heh> SjB, 1990
#       Adds up a column (default=last) of numbers in a file.
#       95/05/16 updated to allow (999) negative style numbers.


case $1 in

-[0-9])

        COLUMN=`echo $1 | tr -d -`

        shift

;;

*)

        COLUMN="NF"

;;

esac

echo "Adding up column .. $COLUMN .. of file(s) .. $*"

nawk  ' OFMT="%.2f"                                       # 1 "%12.2f"

        { x = '$COLUMN'                                   # 2

          neg = index($x, "$")                            # 3

          if (neg > 0) X = gsub("\\$", "", $x)

          neg = index($x, ",")                            # 4

          if (neg > 1) X = gsub(",", "", $x)

          neg = index($x, "(")                            # 8 neg (123 & change

          if (neg > 0) X = gsub("\\(", "", $x)

          if (neg > 0) $x = (-1 * $x)                     # it to "-123.00"

          neg = index($x, "-")                            # 5

          if (neg > 1) $x = (-1 * $x)                     # 6

          t += $x                                         # 7

          print "x is <<<", $x+0, ">>> running balance:", t

        } ' $*


# 1.  set numeric format to eliminate rounding errors
# 1.1 had to reset numeric format from 12.2f to .2f 95/05/16
#     when a computed number is assigned to a variable ( $x = (-1 * $x) )
#     it causes $x to use the OFMT so -1.23 = "________-1.23" vs "-1.23"
#     and that causes my #5 (negative check) to not work correctly because
#     the index returns a number >1 and to the neg neg than becomes a positive
#     this only occurs if the number happened to b a "(" neg number
# 2.  find the field we want to add up (comes from the shell or defaults
#     to the last field "NF") in the file
# 3.  check for a dollar sign ($) in the number - if there get rid of it
#     so we may add it correctly - $12 $1$2 $1$2$ $$1$$2$$ all = 12
# 4.  check for a comma (,) in the number - if there get rid of it so we
#     may add it correctly - 1,2 12, 1,,2 1,,2,, all = 12   (,12=0)
# 5.  check for negative numbers
# 6.  if x is a negative number in the form 999- "make" it a recognized
#     number like -999 - if x is a negative number like -999 already
#     the test fails (y is not >1) and this "true" negative is not made
#     positive
# 7.  accumulate the total
# 8.  if x is a negative number in the form (999) "make it a recognized
#     number like -999
# * Note that a (-9) (neg neg number) returns a postive
# * Mite not work rite with all forms of all numbers using $-,+. etc. *

而不是使用cut从ls -l的输出中获取文件大小，你可以直接使用:

$ cat files.txt | xargs ls -l | awk '{total += $5} END {print "Total:", total, "bytes"}'

Awk将“$5”解释为第五列。这是ls -l中的列，它提供了文件大小。

cat files.txt | awk '{ total += $1} END {print total}'

您可以使用awk来做同样的事情，它甚至会跳过非整数

$ cat files.txt
1
2.3
3.4
ew
1

$ cat files.txt | awk '{ total += $1} END {print total}'
7.7

或者您可以使用ls命令并计算人类可读的输出

$ ls -l | awk '{ sum += $5} END  {hum[1024^3]="Gb"; hum[1024^2]="Mb"; hum[1024]="Kb"; for (x=1024^3; x>=1024; x/=1024) { if (sum>=x) { printf "%.2f %s\n",sum/x,hum[x]; break; } } if (sum<1024) print "1kb"; }'
15.69 Mb

$ ls -l *.txt | awk '{ sum += $5} END  {hum[1024^3]="Gb"; hum[1024^2]="Mb"; hum[1024]="Kb"; for (x=1024^3; x>=1024; x/=1024) { if (sum>=x) { printf "%.2f %s\n",sum/x,hum[x]; break; } } if (sum<1024) print "1kb"; }'
2.10 Mb

python3 -c"import os; print(sum(os.path.getsize(f) for f in open('files.txt').read().split()))"

或者，如果你只是想把这些数字加起来，可以输入:

python3 -c"import sys; print(sum(int(x) for x in sys.stdin))"