Need to read the values of a config file from a shell script - shell

Question

I have a shell script and a common configuration file where all the generic path, username and other values are stored. I want to get the value from this configuration file while I am running the sh script.
example:
sample.conf
pt_user_name=>xxxx
pt_passwd=>Junly#2014
jrnl_source_folder=>x/y/v
pt_source_folder=>/x/y/r/g
css_source_folder=>/home/d/g/h
Now i want get some thing like this in my sh script.
cd $css_source_folder
this command inside the shell script should take me to the location d/g/h while the script is running.
Is there any way to achieve this other than with grep and awk??
Thanks
Rinu

Answer 1

If you want to read from conf file everytime then grep and cut might help you,
suppose you need value for css_source_folder property
prop1="css_source_folder" (I am assuming you know property name whose value you want)
value_of_prop1=`grep $prop1 sample.conf| cut -f2 -d "=" | cut -f2 -d ">"`
like,
[db2inst2#pegdb2 ~]$ vi con.conf
[db2inst2#pegdb2 ~]$ grep css_source_folder con.conf
css_source_folder=>/home/d/g/h
[db2inst2#pegdb2 ~]$ value=`grep css_source_folder con.conf | cut -f2 -d "="`
[db2inst2#pegdb2 ~]$ echo $value
>/home/d/g/h
[db2inst2#pegdb2 ~]$ value=`grep css_source_folder con.conf | cut -f2 -d "=" | cut -f2 -d ">"`
[db2inst2#pegdb2 ~]$ echo $value
/home/d/g/h
If you want to read all properties at once, then apply loop and this will solve the purpose

Answer 2

Yes, you can get the configuration names and values relatively simple and associate them through array indexes. Reading your config can be done like this:
#!/bin/bash
test -r "$1" || { echo "error: unable to read conf file [$1]\n"; exit 1; }
declare -a tag
declare -a data
let index=0
while read line || test -n "$line"; do
tag[index]="${line%%\=*}"
data[index]="${line##*\>}"
((index++))
done < "$1"
for ((i=0; i<${#tag[#]}; i++)); do
printf " %18s %s\n" "${tag[$i]}" "${data[$i]}"
done
After reading the config file, you then have the config name tags and config values stored in the arrays tag and value, respectively:
pt_user_name xxxx
pt_passwd Junly#2014
jrnl_source_folder x/y/v
pt_source_folder /x/y/r/g
css_source_folder /home/d/g/h
At that point, it is a matter of determining how you will use them, whether as a password or as a directory. You may have to write a couple of functions, but the basic function of given a tag, get the correct data can be done like this:
function getvalue {
test -n "$1" || { echo "error in getvalue, no data supplied"; return 1; }
for ((i=0; i<${#tag[#]}; i++)); do
if test "$1" = "${tag[$i]}"; then
echo " eval cmd ${data[$i]}"
return $i
fi
done
return -1
}
echo -e "\nget value for 'jrnl_source_folder'\n"
getvalue "jrnl_source_folder"
The function will return the index of the data value and can execute any command needed. You seem to have directory paths and passwords, so you may need a function for each. To illustrate, the output of the example is:
get value for jrnl_source_folder
eval cmd x/y/v
You can also use an associative array in later versions of BASH to store the tag and data in a single associative array. You may also be able to use indirect references on the tag and data values to process them. I simply took the straight forward approach in the example.

Answer 3

Try this eval $(awk -F'=>' '{print $1"=\""$2"\";"}' sample.conf):
EX:
eval $(awk -F'=>' '{print $1"=\""$2"\";"}' sample.conf); echo $pt_user_name
xxxx
Using sed :
eval $(sed -re 's/=>/="/g' -e 's/$/";/g' sample.conf); echo $pt_passwd
Junly#2014
Using perl :
eval $(perl -F'=>' -alne 'print "$F[0]=\"$F[1]\";"' sample.conf); echo $pt_source_folder
/x/y/r/g
Using tr :
eval $(tr -d '>' <sample.conf); echo "$css_source_folder"
/home/d/g/h
PS. Using tr blindly to remove > may cause undesirable results depending on the content of sample.conf, but for the one provided works fine.