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Creating variables in bash

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# 1  
Old 04-19-2012
Creating variables in bash
I am writing some scripts using bash and am wondering if there is a better way to perform the following set of formatting variables.

Code:
s1=" "
s2="  "
s3="   "
s4="    "
s5="     "
s6="      "
s7="       "
s8="        "
 
frmt_titl="${bYl}%s${nClor}\n"

frmt1_titl="${s1}$frmt_titl"
frmt2_titl="${s2}$frmt_titl"
frmt3_titl="${s3}$frmt_titl"
frmt4_titl="${s4}$frmt_titl"
frmt5_titl="${s5}$frmt_titl"
frmt6_titl="${s6}$frmt_titl"
frmt7_titl="${s7}$frmt_titl"
frmt8_titl="${s8}$frmt_titl"

nfrmt_titl="\n$frmt_titl"
nfrmt1_titl="\n$frmt1_titl"
nfrmt2_titl="\n$frmt2_titl"
nfrmt3_titl="\n$frmt3_titl"
nfrmt4_titl="\n$frmt4_titl"
nfrmt5_titl="\n$frmt5_titl"
nfrmt6_titl="\n$frmt6_titl"
nfrmt7_titl="\n$frmt7_titl"
nfrmt8_titl="\n$frmt8_titl"

# 2  
Old 04-19-2012
Try this:
Code:
$ w=12; printf "%${w}s\n" hello
       hello
$ w=20; printf "%${w}s\n" hello
               hello

# 3  
Old 04-19-2012
It looks interesting. I will be doing something as shown below:

Code:
  printf "$frmt4_titl" "NAME"

which gives yellow color text with 4 spaces in the front

I do not want to have a long line. The idea is that I write relatively short format string, followed by the things I want to print.

I essence, I want to construct the format variables above in a better way.

---------- Post updated at 03:26 PM ---------- Previous update was at 03:22 PM ----------

Can I construct a variable name with a counter using a loop?

---------- Post updated at 03:34 PM ---------- Previous update was at 03:26 PM ----------

Quote:
Originally Posted by Scrutinizer
Try this:
Code:
$ w=12; printf "%${w}s\n" hello
       hello
$ w=20; printf "%${w}s\n" hello
               hello

I have been thinking a bit more and variable names in shell are not designed to be dynamically created. So I suppose I would need to keep the code not much different.
# 4  
Old 04-19-2012
You can use eval (or indirect references in bash/ksh93), but you need to be careful with security, especially with user input or input files...

Code:
$ for i in 1 2 3; do eval var$i=$((i*10)); done
$ echo $var1 $var2 $var3
10 20 30

# 5  
Old 04-19-2012
What do you think of using

Code:
export

Example

Code:
i=4
s4="    "
frmt_titl="${bYl}%s${nClor}\n"
export frmt${w}_titl="${s4}$frmt_titl"




---------- Post updated at 03:46 PM ---------- Previous update was at 03:44 PM ----------

Quote:
Originally Posted by Scrutinizer
You can use eval (or indirect references in bash/ksh93), but you need to be careful with security, especially with user input or input files...

Code:
$ for i in 1 2 3; do eval var$i=$((i*10)); done
$ echo $var1 $var2 $var3
10 20 30

I am planning to define all this stuff in a bash file. Then source it, so that I can use the variables from another script.

---------- Post updated at 03:49 PM ---------- Previous update was at 03:46 PM ----------

Code:


Code:



cat utility.bash

#!/bin/bash
for i in 1 2 3; do eval var$i=$((i*10)); done









Code:



cat test.bash

#!/bin/bash
source utility.bash
echo "$var1"

# 6  
Old 04-19-2012
What's wrong with using printf? You can tell it how wide to make a field, instead of stuffing 20 spaces in one string, 19 in another, 18 in another...
# 7  
Old 04-19-2012
There is nothing wrong with using printf. In fact I will use it. What I am trying to do is specify the format to printf. Then in my main script I call printf followed by the format string, followed by the strings to output. Else things will get too long if I put the actual format.

Example
Code:
printf "format" "str1" "str2" "str3" "str4" "str5"

The thing is that the output of str1 str2 str3 might also be of different colors which makes the format specification very long

As an example, the example might print as

str1, str2, str3, str4 str5
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