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I have a bash script where I define UTF-8 Greek Symbols in a file named greek-utfb.sh. I want to run tests that display the variables for printing the greek letters in the file greek-utfb-scout.

--- greek-utfb.sh ----

utfb-greek () { Alph="\u0391" # Alpha Beta="\u0392" # Beta Gamm="\u0393" # Gamma Delt="\u0394" # Delta Epsi="\u0395" # Epsilon }

--- greek-utfb-scout.sh ---

greek-utf-scout () { echo -e "Alph: $Alph" echo -e "Beta: $Beta" echo -e "Gamm: $Gamm" echo -e "Delt: $Delt" echo -e "Epsi: $Epsi" }

What do I have to add in greek-utfb-scout.sh to be able to translate the greek variables in greek-utfb.sh.

Isabel
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1 Answers1

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First, don't put the variable definitions inside a function. Instead, change greek-utfb.sh to look like this:

#!/bin/sh
Alph="\u0391"   # Alpha
Beta="\u0392"   # Beta
Gamm="\u0393"   # Gamma
Delt="\u0394"   # Delta
Epsi="\u0395"   # Epsilon

Now source this file in greek-utfb-scout.sh:

#!/bin/sh

. greek-utfb.sh

greek-utf-scout () { echo -e "Alph: $Alph" echo -e "Beta: $Beta" echo -e "Gamm: $Gamm" echo -e "Delt: $Delt" echo -e "Epsi: $Epsi" }

After running . greek-utfb-scout.sh, the function now works as expected:

$ . greek-utfb-scout.sh
$ greek-utf-scout
Alph: Α
Beta: Β
Gamm: Γ
Delt: Δ
Epsi: Ε
Panki
  • 6,664
  • More info: What's the meaning of a dot before a command in shell? source and . builtins are synonyms in Bash; . is the portable one. If the shebang of the "calling" script is #!/bin/sh then you should use .. +1 anyway because sourcing is the answer. – Kamil Maciorowski Aug 12 '21 at 10:04
  • @KamilMaciorowski Thanks for that, I changed the answer to use . instead. – Panki Aug 12 '21 at 10:40
  • I have many variables that define the utf-8 codes (greek, cyrillic, math, arrows). Because I want to enable them when I am using them, I have put them inside a function. In this way I can instantiate the codes that I want to use only. Is there a way to release the memory after I am done using them? – Isabel Aug 12 '21 at 11:28
  • You can use unset Alph to clear the $Alph variable. – Panki Aug 12 '21 at 11:31
  • It's not worth worrying about releasing the memory unless you expect the script to be running for a very long time (days, weeks, or months), and probably not even then. Even if you have thousands of such variables defined, it's not going to use enough RAM to care about. – cas Aug 12 '21 at 14:55
  • Do you know how to compute the amount of memory a shell variable holds? – Isabel Aug 12 '21 at 17:46
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    The size of the string plus a few bytes (cue "how long is a piece of string?" joke), which depends on what's in the string variable and how many bytes each character takes. Without details, one can only guess: best case, a few thousand bytes for all your vars. worst case, several hundred thousand bytes or even a few million. On a system with probably gigabytes of memory, that's irrelevant. A potentially bigger problem than memory usage is the efficiency of the tree structure and algorithm used to store and access thousands or tens/hundreds of thousands of variable names and their values. – cas Aug 13 '21 at 02:51
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    and even that's not worth worrying about. shell is not a language noted for its speed or efficiency, and if you're writing scripts where memory usage or speed are a problem, then it's time to use a different language. awk, perl, python, C, whatever. shell just does not scale to large or complicated problems. its job is to co-ordinate the execution of other programs, passing data to the via command-line args, files, pipes, redirections, and the like. – cas Aug 13 '21 at 02:54