Bourne Shell For i in (seq)

问题:

I want to write a loop in Bourne shell which iterates a specific set of numbers. Normally I would use seq:

for i in `seq 1 10 15 20`
   #do stuff
loop

But seemingly on this Solaris box seq does not exist. Can anyone help by providing another solution to iterating a list of numbers?

回答1:

try

for i in 1 10 15 20
do
   echo "do something with $i"
done

else if you have recent Solaris, there is bash 3 at least. for example this give range from 1 to 10 and 15 to 20

for i in {1..10} {15..20}
do
  echo "$i"
done

OR use tool like nawk

for i in `nawk 'BEGIN{ for(i=1;i<=10;i++) print i}'`
do
  echo $i
done

OR even the while loop

while [ "$s" -lt 10 ]; do s=`echo $s+1|bc`; echo $s; done

回答2:

You can emulate seq with dc:

For instance:

seq 0 5 120

is rewritten as:

dc -e '0 5 120  1+stsisb[pli+dlt>a]salblax'

回答3:

Another variation using bc:

for i in $(echo "for (i=0;i<=3;i++) i"|bc); do echo "$i"; done

For the Bourne shell, you'll probably have to use backticks, but avoid them if you can:

for i in `echo "for (i=0;i<=3;i++) i"|bc`; do echo "$i"; done

回答4:

I find that this works, albeit ugly as sin:

for i in `echo X \n Y \n Z ` ...

回答5:

for i in `seq 1 5 20`; do echo $i; done

Result:

5
10
15
20

$ man seq

SEQ(1)                           User Commands                          SEQ(1)

NAME
       seq - print a sequence of numbers

SYNOPSIS
       seq [OPTION]... LAST
       seq [OPTION]... FIRST LAST
       seq [OPTION]... FIRST INCREMENT LAST