BASH script segment won't work in larger script

[EdH]

Originally Posted by paulunderwood

#!/bin/bash

a="31363920 948583258055568 -21094061301960794201597 -101781123694367174730692456309 1859252514529139843616145918243322920 1347307311985305327578340438707291179185984 951738172269489471300643 -167704995415343890580296180142353038"
echo "$a" > testcase
#exec < "testcase"
read b < testcase 
c="31363920"
d="${a:0:8}"
e="${b:0:8}"
m="3"

echo "m is $m and d is $d and c is $c and b is ${b:0:10}... and a is ${a:0:10}..."
printf "\nYAFU says $c*$m is "
../yafu/yafu "expr($c*$m)" -silent
printf "\nYAFU says $d*$m is "
../yafu/yafu "expr($d*$m)" -silent
printf "\nYAFU says $e*$m is "
../yafu/yafu "expr($e*$m)" -silent

results in:

m is 3 and d is 31363920 and c is 31363920 and b is 31363920 9... and a is 31363920 9...

YAFU says 31363920*3 is 94091760

YAFU says 31363920*3 is 94091760

YAFU says 31363920*3 is 94091760

Idea lifted from https://linuxhint.com/read_file_line_by_line_bash/

(I compiled msieve for YAFU without zlib.)

Excellent! But, I'm still a bit confused as to how to read subsequent lines from testcase. In my original version, I'm trying to use:

exec <"testcase"
  while read line
    do
      larray=($line)
      ../../yafu/yafu with some elements of the array
    done

How do I acquire subsequent lines using "read b < testcase?"


Thanks.

[paulunderwood]

Originally Posted by EdH

Excellent! But, I'm still a bit confused as to how to read subsequent lines from testcase. In my original version, I'm trying to use:

exec <"testcase"
while read line
    do
      larray=($line)
      ../../yafu/yafu with some elements of the array
    done

How do I acquire subsequent lines using "read b < testcase?"


Thanks.

Just move the input redirection to after done like this:

while read line
    do
      larray=($line)
      ../../yafu/yafu with some elements of the array
    done < testcase

[EdH]

#!/bin/bash

a="31363920 948583258055568 -21094061301960794201597 -101781123694367174730692456309"
echo "$a" > testcase
echo "22$a" >> testcase
c="31363920"
m="3"

printf "\nYAFU says $c*$m is "
../../yafu/yafu "expr($c*$m)" -silent

while read line
  do
    larray=($line)
    d=${larray[0]}
    echo "d is $d"
    printf "YAFU says $d*$m is "
    ../../yafu/yafu "expr($d*$m)" -silent
  done < testcase

gives me this:

YAFU says 31363920*3 is 94091760
d is 31363920
YAFU says 31363920*3 is no variable indicator (@): interpreting batchfile lines as input expressions
-101778913424507528108228602338
eof; done processing batchfile

I'm going to have to set this aside for the night and hit it fresh tomorrow. Sorry I'm not getting this, but thanks for trying to help me out.

I have also tried reading a complete file, but YAFU still seems to act the same. If I can make sure the file is closed after, maybe I can use a two-dimension array and read the entire file into the program and work from there. But, it seems that the flag kruoli pointed out isn't reset once it's opened.

[paulunderwood]

a="31363920 948583258055568 -21094061301960794201597 -101781123694367174730692456309"
echo "$a" > testcase
echo "22$a" >> testcase
c="31363920"
m="3"

printf "\nYAFU says $c*$m is "
../../yafu/yafu "expr($c*$m)" -silent

readarray matrix < testcase
#file now closed

for row in "${matrix[@]}";do                                                      
    row_matrix=(${row})                                                            
    d=${row_matrix[0]}                                                         
    echo "d is $d"
    printf "YAFU says $d*$m is "
    ../../yafu/yafu "expr($d*$m)" -silent
done

This reads entire file and picks d as the first of each row.

YAFU says 31363920*3 is 94091760
d is 31363920
YAFU says 31363920*3 is 94091760
d is 2231363920
YAFU says 2231363920*3 is 6694091760

[EdH]

I've successfully coded a stand alone script that works well. I have not attempted to incorporate the code into a function in the main script. Perhaps a little later.

Thanks for all the help.

[EdH]

Well, unfortunately, in practice, it just doesn't work!

From the command line, the stand alone script works as it should. But, as a function within the bigger script, or as a call to the working script from within the bigger script, YAFU fails to understand. I'm guessing it's just due to the flag being set by something in the bigger script.

My work around is fine for now, so I'm not going to spend any more time with it until "maybe" later.


Thanks everyone.

[EdH]

Just a final note to my "adventure," since there is a conclusion:

First, YAFU was never "portable" enough for my need. I found that even changing to a parallel directory caused it to output differently. Since I intend the script I'm working on to be available to others, I had to give up on YAFU. To be fair, YAFU was not the correct choice from the start for such a task.

The good news is that Pari-gp is readily available and much easier to implement for my script. The new code is simply:

ans=$(echo "$d*$m" | gp -q -f)

It returns, in $ans, the clean value of the multiplication of the two input values, works everywhere tested and is not affected by open files.

Thanks for all the help from everyone.

[paulunderwood]

Originally Posted by EdH

The good news is that Pari-gp is readily available and much easier to implement for my script. The new code is simply:

ans=$(echo "$d*$m" | gp -q -f)

It returns, in $ans, the clean value of the multiplication of the two input values, works everywhere tested and is not affected by open files.

For lengthy numbers you might find this is better as there is no truncation:

ans=$(echo "print($d*$m)" | gp -q -f)

[EdH]

Originally Posted by paulunderwood

For lengthy numbers you might find this is better as there is no truncation:

ans=$(echo "print($d*$m)" | gp -q -f)

Thanks! That is important.