Bash: "invalid number" error when passing array elements value to variable

Question

I run GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu). A very simple script called from cmd line with at least 3 arbitrary arguments:

#!/bin/bash

n_arg=$#
arr=("$@") 
AA=${arr[0]}   # CHANGED FROM AA=S{arr[0]}
BB=${arr[1]}   # CHANGED FROM BB=S{arr[1]}

for (( i = 2; i < "$n_arg"; i++ )); do
    printf "%d   %s   %s   %s\n" $i $AA $BB  ${arr[i]}  # <- line 9
    # printf "%d   %s   %s   %s\n" $i "$AA" "$BB"  ${arr[i]}  # ALSO TRIED
done
exit 0

yields an error as shown below:

$ script.sh 10 2 13 443
./script.sh: line 9: printf: S{arr[0]}: invalid number
./script.sh: line 9: printf: S{arr[1]}: invalid number
2    0   0   13
./script.sh: line 9: printf: S{arr[0]}: invalid number
./script.sh: line 9: printf: S{arr[1]}: invalid number
3    0   0   443

I can see that the value of the first and second array elements passed to AA and BB respectively seems to pose a prbm I don't quite scope. I did try: AA="S{arr[0]}" When I type in the code in interactive mode, everything goes smoothly.

S? Do you mean $? As, in AA=${arr[0]}

bishop
– bishop

2015-06-23 20:44:09 +00:00
Commented Jun 23, 2015 at 20:44 — bishop
– bishop, Commented Jun 23, 2015 at 20:44
Sounds like you need glasses or a better font. =)

Etan Reisner
– Etan Reisner

2015-06-23 20:45:01 +00:00
Commented Jun 23, 2015 at 20:45 — Etan Reisner
– Etan Reisner, Commented Jun 23, 2015 at 20:45
ProggyFont rules.

bishop
– bishop

2015-06-23 20:45:36 +00:00
Commented Jun 23, 2015 at 20:45 — bishop
– bishop, Commented Jun 23, 2015 at 20:45

bishop · Accepted Answer · 2015-06-23 20:53:06Z

1

S looks like $, especially when you're tired. I use a font designed to clearly distinguish homoglyphs like that -- highly recommended.

Arrays are not part of the POSIX shell standard. You can roll your own polyfill, or use a pre-fab one.

answered Jun 23, 2015 at 20:53

bishop

39.8k14 gold badges116 silver badges150 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Cbhihe Over a year ago

Just a vaguely lame and off topic but real short comment: .... I took yr advice and downloaded/installed the proggy TTF. It looks really bad in terminal on my 1680x1050 display, because due to high screen res I have to increase font size from default 12 to 16 to be able to read clearly ... So unless there is a solution to legibly scale TTF available in terminal , it's a no go for me. Pity but advice much appreciated.

bishop Over a year ago

@Cbhihe Similar situation here, 1920x1080 FHD, the font looks jagged at high point size. I've come to consider that a benefit, though. Not only do I get a bit of daily nostalgia from the 1993 BBS feel (which even strangers comment on), but I can clearly read it from far away with my wireless keyboard. But I guess it's like snails in butter -- an acquired taste. That said, there are a few really good anti-aliased monospace programmer's fonts. Here's a great article listing 10 of them.

Collectives™ on Stack Overflow

Bash: "invalid number" error when passing array elements value to variable

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related