如何使用Perl多次运行同一命令？

Question

I have 2 commands that I need to run back to back 16 times for 2 sets of data. I have labeled the files used as file#a1_100.gen (set 1) and file#a2_100.gen (set 2). The 100 is then replaced by multiples of 100 upto 1600 (100,200,...,1000,...,1600).

Example 1: For first set

Command 1: perl myprogram1.pl file#a1.pos abc#a1.ref xyz#a1.ref file#a1_100.gen file#a1_100.out

Command 2: perl my program2.pl file#a1_100.out file#a1_100.out.long

Example 2: For first set

Command 1: perl myprogram1.pl file#a1.pos abc#a1.ref xyz#a1.ref file#a1_200.gen file#a1_200.out

Command 2: perl my program2.pl file#a1_200.out file#a1_200.out.long

These 2 commands are repeated 16 times for both set 1 and set 2. For set 2 the filename changes to File#a2...

I need a command that will run this on its own by changing the filename for the 2 sets, running it 16 times for each set.

Any help will be greatly appreciated! Thanks!

Answer 1

This is probably most easily done with a shell script. As with Perl, TMTOWTDI — there's more than one way to do it.

for num in $(seq 1 16)
do
    perl myprogram1.pl file#a1.pos abc#a1.ref xyz#a1.ref file#a1_${num}00.gen file#a1_${num}00.out
    perl myprogram2.pl file#a1_${num}00.out file#a1_${num}00.out.long
done

(You could use {1..16} in place of $(seq 1 16) to generate the numbers. You might also note that the # characters in the file names discombobulate the SO Markdown system.)

Or you could use:

for num in $(seq 100 100 1600)
do
    perl myprogram1.pl file#a1.pos abc#a1.ref xyz#a1.ref file#a1_${num}.gen file#a1_${num}.out
    perl myprogram2.pl file#a1_${num}.out file#a1_${num}.out.long
done

(I don't think there's a {...} expansion for that.)

Or, better, you could use variables to hold values to avoid repetition:

POS="file#a1.pos"
ABC="abc#a1.ref"
XYZ="xyz#a1.ref"

for num in $(seq 100 100 1600)
do
    PFX="file#a1_${num}"
    GEN="${PFX}.gen"
    OUT="${PFX}.out"
    LONG="${OUT}.long"
    perl myprogram1.pl "${POS}" "${ABC}" "${XYZ}" "${GEN}" "${OUT}"
    perl myprogram2.pl "${OUT}" "${LONG}"
done

In this code, the braces around the parameter names are all optional; in the first block of code, the braces around ${num} were mandatory, but optional in the second set. Enclosing names in double quotes is also optional here, but recommended.

Or, if you must do it in Perl, then:

use warnings;
use strict;

my $POS = "file#a1.ref";
my $ABC = "abc#a1.ref";
my $XYZ = "xyz#a1.ref";

for (my $num = 100; $num <= 1600; $num += 100)
{
    my $PFX = "file#a1_${num}";
    my $GEN = "${PFX}.gen";
    my $OUT = "${PFX}.out";
    my $LONG = "${OUT}.long";
    system("perl", "myprogram1.pl", "${POS}", "${ABC}", "${XYZ}", "${GEN}", "${OUT}");
    system("perl", "myprogram2.pl", "${OUT}", "${LONG}");
}

This is all pretty basic coding. And you can guess that it didn't take me long to generate this from the last shell script. Note the use of multiple separate strings instead on one long string in the system calls. That avoids running a shell interpreter — Perl runs perl directly.

You could use $^X instead of "perl" to ensure that you run the same Perl executable as ran the script shown. (If you have /usr/bin/perl on your PATH but you run $HOME/perl/v5.20.1/bin/perl thescript.pl , the difference might matter, but probably wouldn't.)