CODEWITHSUNDEEP
bash
ex1led
ex1led

Reputation: 469

Read from File into an Array

I am writing a bash script that does various stuff but when it starts, it checks if there has been a crash and so tries to load its variables from a logfile.

The log file has the following format:

1stline: var1:var2:var3:var4:var5 # : is a delimeter
2ndline: number                   # [0-9]
3rdline: var6:var7:var8           # : is a delimeter

So as you can tell I have 9 variables that I wish to load from this file if there has been a crash.

I am trying to write some code in bash to do it but I am getting stuck.

For instance my Idea is to create an array, and add every variable which is read from the logfile there. But I am having troubles writing this code. 

if [ -s ${crashfile} ] # file exists => crash has occured
then
    declare -a loadvars
    while IFS= read -r line 

        # What do I do in here ? 

    done < ${crashfile}

else # file doesn't exist => cold start

# bla 
# bla
# bla

fi

The problem is focused inside the first while loop. Meaning I am thinking that I have to create another while loop to tokenize the string accordingly? But then again, the second line has only a number with no delimeter so this should be treated carefully aswell?

I can do it with python/C whatever but the point is to do it with bash.

Thanks in advance.

Upvotes: 0

Views: 95

Answers (2)

L&#233;a Gris
L&#233;a Gris

Reputation: 19545

If you are really sure of your 9 variables:

IFS=$':\n' read -r -d '' var1 var2 var3 var4 var5 number var6 var7 var8

printf '<%s>\n' "$var1" "$var2" "$var3" "$var4" "$var5" "$number" "$var6" "$var7" "$var8"

If you need to read an undefined amount of values, then use an array:

IFS=$':\n' read -r -d '' -a vars

printf '<%s>\n' "${vars[@]}"

Upvotes: 1

oguz ismail
oguz ismail

Reputation: 50750

Using a temporary array:

vars=()
while IFS=: read -ra temp; do
    vars+=("${temp[@]}")
done < file
printf '<%s>\n' "${vars[@]}"

For your sample (except # comments), it outputs:

<var1>
<var2>
<var3>
<var4>
<var5>
<number>
<var6>
<var7>
<var8>

Upvotes: 3

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