Consider the below example:
Parameter1 = 5
Parameter2 = 10
Parameter3 = 15
Parameter4 = 20
I want to fetch the value depending on the parameter name by providing a user input as shown below:
echo ""
echo " Enter the parameter name"
read value
Parameter = "$value"
Check if the parameter is existing within the concern file
if grep -qs "$Parameter" "Filename"
then
echo " Parameter exist within the concern file"
val = #Here I want to fetch the value of the parameter that the user had input and I do not know how to do it?
Kindly let me know how I can fetch the value of the parameter which the user had given as input.
If I understand you correctly, you could use something like this:
read param_name # e.g. Parameter2
value=$(awk -v param="$param_name" '$1 == param { print $3 }' filename)
This reads the name of the parameter then prints the third field on the line when the first field matches the name. The result is assigned to the shell variable $value.
Related
I have a file file.dat as follow:
1.1,2.1 1.4
3.1,2.1 2.4
2.4,4.5 11.5
..
And I want to select each time the whole line (string) and replace it in another file. So far I tried the following
#!/bin/csh
set FILENAME = 'file.dat' # file in which the strings are
set str = "229.8,230.9 230.36" # initialize the first string
set n = 1
while ( $n <= 3 ) # number of lines in the FILENAME
echo Testing the first string $str
set rep = $(head -n $n "$FILENAME")
# n++ # increment the index
end
When I tried to launch the script csh launch.sh I obtained the follow error message
Testing the first string 229.8,230.9 230.36
Illegal variable name. # connect with the rep definition(?)
The file in which I want to change the string str is as follow (this is btw a secondary problem which I could figure out by myself once I understand what's wrong in the first lines):
# Name Type Par
Mi FI 154.2355189465
So UN 229.8,230.9 230.36 # line to be changed
Za FI 0.8000020209
May somebody help me, please?
$(...) is Bash syntax for command substitution in Bash.
In C-shell you have to use backticks instead (yuck).
I'm a few weeks into bash scripting and I haven't advanced enough yet to get my head wrapped around this problem. Any help would be appreciated!
I have a "script.conf" file that contains the following:
key1=value1
key2=${HOME}/Folder
key3=( "k3v1" "k3 v2" "k3v3")
key4=( "k4v1"
"k4 v2"
"k4v3"
)
key5=value5
#key6="Do Not Include Me"
In a bash script, I want to read the contents of this script.conf file into an array. I've learned how to handle the scenarios for keys 1, 2, 3, and 5, but the key4 scenario throws a wrench into it with it spanning across multiple lines.
I've been exploring the use of sed -n '/=\s*[(]/,/[)]/{/' which does capture key4 and its value, but I can't figure out how to mix this so that the other keys are also captured in the matches. The range syntax is also new to me, so I haven't figured out how to separate the key/value. I feel like there is an easy regex that would accomplish what I want... in plain-text: "find and group the pattern ^(.*)= (for the key), then group everything after the '=' char until another ^(.*)= match is found, rinse and repeat". I guess if I do this, I need to change the while read line to not handle the key/value separation for me (I'll be looking into this while I'm waiting for a response). BTW, I think a solution where the value of key4 is flattened (new lines removed) would be acceptable; I know for key3 I have to store the value as a string and then convert it to an array later when I want to iterate over it since an array element apparently can't contain a list.
Am I on the right path with sed or is this a job for awk or some other tool? (I haven't ventured into awk yet). Is there an easier approach that I'm missing because I'm too deep into the forest (like changing the while read line in the LoadConfigFile function)?
Here is the code that I have so far in script.sh for processing and capturing the other pairs into the $config array:
__AppDir=$(dirname $0)
__AppName=${__ScriptName%.*}
typeset -A config #init config array
config=( #Setting Default Config values
[key1]="defaultValue1"
[key2]="${HOME}/defaultFolder"
[QuietMode]=0
[Verbose]=0 #Ex. Usage: [[ "${config[Verbose]}" -gt 0 ]] && echo ">>>Debug print"
)
function LoadConfigFile() {
local cfgFile="${1}"
shopt -s extglob #Needed to remove trailing spaces
if [ -f ${cfgFile} ]; then
while IFS='=' read -r key value; do
if [[ "${key:0:1}" == "#" ]]; then
#echo "Skipping Comment line: ${key}"
elif [ "${key:-EMPTY}" != "EMPTY" ]; then
value="${value%%\#*}" # Delete in-line, right comments
value="${value%%*( )}" # Delete trailing spaces
value="${value%%( )*}" # Delete leading spaces
#value="${value%\"*}" # Delete opening string quotes
#value="${value#\"*}" # Delete closing string quotes
#Manipulate any variables included in the value so that they can be expanded correctly
# - value must be stored in the format: "${var1}". `backticks`, "$var2", and "doubleQuotes" are left as is
value="${value//\"/\\\"}" # Escape double quotes for eval
value="${value//\`/\\\`}" # Escape backticks for eval
value="${value//\$/\\\$}" # Escape ALL '$' for eval
value="${value//\\\${/\${}" # Undo the protection of '$' if it was followed by a '{'
value=$(eval "printf '%s\n' \"${value}\"")
config[${key}]=${value} #Store the value into the config array at the specified key
echo " >>>DBG: Key = ${key}, Value = ${value}"
#else
# echo "Skipped Empty Key"
fi
done < "${cfgFile}"
fi
}
CONFIG_FILE=${__AppDir}/${__AppName}.conf
echo "Config File # ${CONFIG_FILE}"
LoadConfigFile ${CONFIG_FILE}
#Print elements of $config
echo "Script Config Values:"
echo "----------------------------"
for key in "${!config[#]}"; do #The '!' char gets an array of the keys, without it, we would get an array of the values
printf " %-20s = %s\n" "${key}" "${config[${key}]}"
done
echo "------ End Script Config ------"
#To convert to an array...
declare -a valAsArray=${config[RequiredAppPackages]} #Convert the value from a string to an array
echo "Count = ${#valAsArray[#]}"
for itemCfg in "${valAsArray[#]}"; do
echo " item = ${itemCfg}"
done
As I mentioned before, I'm just starting to learn bash and Linux scripting in general, so if you see that I'm doing some taboo things in other areas of my code too, please feel free to provide feedback in the comments... I don't want to start bad habits early on :-).
*If it matters, the OS is Ubuntu 14.04.
EDIT:
As requested, after reading the script.conf file, I would like for the elements in $config[#] to be equivalent to the following:
typeset -A config #init config array
config=(
[key1]="value1"
[key2]="${HOME}/Folder"
[key3]="( \"k3v1\" \"k3 v2\" \"k3v3\" )"
[key4]="( \"k4v1\" \"k4 v2\" \"k4v3\" )"
[key5]="value5"
)
I want to be able to convert the values of elements 'key4' and 'key3' into an array and iterated over them the same way in the following code:
declare -a keyValAsArray=${config[keyN]} #Convert the value from a string to an array
echo "Count = ${#keyValAsArray[#]}"
for item in "${keyValAsArray[#]}"; do
echo " item = ${item}"
done
I don't think it matters if \n is preserved for key4's value or not... that depends on if declare has a problem with it.
A shell is an environment from which to call tools with a language to sequence those calls. It is NOT a tool to manipulate text. The standard UNIX tool to manipulate text is awk. Trying to manipulate text in shell IS a bad habit, see why-is-using-a-shell-loop-to-process-text-considered-bad-practice for SOME of the reasons why
You still didn't post the expected result of populating the config array so I'm not sure but I think this is what you wanted:
$ cat tst.sh
declare -A config="( $(awk '
{ gsub(/^[[:space:]]+|([[:space:]]+|#.*)$/,"") }
!NF { next }
/^[^="]+=/ {
name = gensub(/=.*/,"",1)
value = gensub(/^[^=]+=/,"",1)
n2v[name] = value
next
}
{ n2v[name] = n2v[name] OFS $0 }
END {
for (name in n2v) {
value = gensub(/"/,"\\\\&","g",n2v[name])
printf "[%s]=\"%s\"\n", name, value
}
}
' script.conf
) )"
declare -p config
$ ./tst.sh
declare -A config='([key5]="value5" [key4]="( \"k4v1\" \"k4 v2\" \"k4v3\" )" [key3]="( \"k3v1\" \"k3 v2\" \"k3v3\")" [key2]="/home/Ed/Folder" [key1]="value1" )'
The above uses GNU awk for gensub(), with other awks you'd use [g]sub() instead.
So, I am trying to get information out of OS X's "favorite servers" .plist so that I can then decide whether or not I want to add certain servers to it. Some of the information for how this can be done can be found here:
http://jacobsalmela.com/bash-script-set-favorite-servers-in-connect-to-menu/
The problem with this is that you can't, for example, just do
/usr/libexec/Plistbuddy -c "Add favoriteservers:CustomListItems:0:Name string server1.fqdn.com" com.apple.sidebarlists.plist
over and over, because Plistbuddy is not smart enough to do an insert into the array. You have to know how long the array is, and then add things to the end of it, such that when you go to add things you have already determined whether you need to use 0 or 5 or 7 between "CustomListItems" and "Name" up there.
The obnoxiousness of that aside, I'm having trouble just parsing the output from the Plistbuddy print command, which looks like this:
Array { Dict { Name = afp://or-fs-001/vol1 URL = afp://or-fs-001/vol1 } Dict { Name = smb://or-fs-001/vol1 URL = smb://or-fs-001/vol1 } Dict { Name = vnc://or-fs-001/vol1 URL = vnc://or-fs-001/vol1 } Dict { Name = ftp://or-fs-001/vol1 URL = ftp://or-fs-001/vol1 } }
So you have the same URL twice for each entry (I have no idea why there is both a "Name" and "URL" when you can't actually make them different), and they may start with any protocol supported by Finder, which means afp, http, https, smb, or vnc. The first thing I'm trying to do is just split them up into pieces by the "Name" substring so that I know how many entries are in the list, but that results in weird behavior when I use tr for that; it starts cutting out way too many pieces.
Does anyone have ideas for better ways to do this? Can I count the number of times "Dict" shows up?
You can use grep -o to extract interesting parts of the input. An example:
#!/bin/bash
output='Array { Dict { Name = afp://or-fs-001/vol1 URL = afp://or-fs-001/vol1 } Dict { Name = smb://or-fs-001/vol1 URL = smb://or-fs-001/vol1 } Dict { Name = vnc://or-fs-001/vol1 URL = vnc://or-fs-001/vol1 } Dict { Name = ftp://or-fs-001/vol1 URL = ftp://or-fs-001/vol1 } }'
count=$(echo "$output" | grep -o 'Name =' | wc -l)
names=($(grep -o 'Name = [^ ]\+' <<< "$output" | cut -f3- -d' '))
echo $count = ${#names[#]}
for name in "${names[#]}" ; do
echo "$name"
done
I have a doubt. When i declare a value and assign to some variable, I don't know how to reassign the same value to another variable. See the code snippet below.
#/bin/sh
#declare ARG1 to a
a=ARG1
#declaring $a to ARG2
ARG2=$`$a`
echo "ARG 2 = $ARG2"
It should display my output as
ARG 2 = ARG1
...but instead the actual output is:
line 5: ARG1: command not found
ARG 2 = $
To assign the value associated with the variable dest to the variable source, you need simply run dest=$source.
For example, to assign the value associated with the variable arg2 to the variable a:
a=ARG1
arg2=$a
echo "ARG 2 = $arg2"
The use of lower-case variable names for local shell variables is by convention, not necessity -- but this has the advantage of avoiding conflicts with environment variables and builtins, both of which use all-uppercase names by convention.
You may also want to alias rather than copy the variable. For example, if you need mutation. Or if you want to run a function multiple times on different variables. Here's how it works
Example:
C=cat
declare -n VAR=C
VAR+=" says Hi"
echo "$C" # prints "cat says Hi"
Example with arrays/dictionaries:
A=(a a a)
declare -n VAR=A # "-n" stands for "name", e.g. a new name for the same variable
VAR+=(b)
echo "${A[#]}" # prints "a a a b"
That is, VAR becomes effectively the same as the original variable. Instead of copying, you're adding an alias. Here's an example with functions:
function myFunc() {
local -n VAR="$1"
VAR="Hello from $2"
echo "I've set variable '$1' to value '$VAR'"
}
myFunc Inbox Bob # I've set variable 'Inbox' to value 'Hello from Bob'
myFunc Luke Leia # I've set variable 'Luke' to value 'Hello from Leia'
echo "$Luke" # Hello from Leia
Whether you should use these approaches is a question. Generally, immutable code is easier to read and to reason about (in almost any programming language). However, sometimes you really need to get stuff done in a certain way. Hope this answer helps you then.
I have a csv file which im trying to loop through with the purpose to find out if an User Input is found inside the csv data. I wrote the following code which sometimes works and others doesn't. It always stops working when I try to compare to a 2+ digit number. It works OK for numbers 1 through 9, but once u enter lets say 56 , or 99 or 100, it stops working.
the csv data is comma delimited, i have about 300 lines they are just like this.
1,John Doe,Calculus I,5.0
1,John Doe,Calculus II,4.3
1,John Doe,Physics II,3.5
2,Mary Poppins,Calculus I,3.7
2,Mary Poppins,Calculus II,4.7
2,Mary Poppins,Physics I,3.7
Data is just like that, all the way down until ID #100 for a total of 300 lines. Both the sh file and csv file are in the same folder, I'm using a fresh installation of Ubuntu 12.04.3, using gedit as the text editor.
I tried Echoing the variables ID and inside the IF conditionals but it doesn't behave the way it should when testing for the same value. Could someone point me out in the right direction. Thanks
Here's the code:
#s!/bin/bash
echo "enter your user ID";
read user;
INPUT_FILE=notas.csv
while IFS="," read r- ID name asignature final;
do
if [$ID = $user]; then
userType=1;
else
userType=2;
fi
done < notas.csv
Well, your code as written has a few issues.
You have r- instead of -r on the read line - I assume that's a typo not present in your actual code or you wouldn't get very far.
Similarly, you need space around the [...] brackets: [$ID is a syntax error.
You need to quote the parameter expansions in your if clause, and/or switch bracket types. You probably make it a numeric comparison as #imp25 suggested, which I would do by using ((...)).
You probably don't want to set userType to 2 in an else clause, because that will set it to 2 for everyone except whoever is listed last in the file (ID 100, presumably). You want to set it to 2 first, outside the loop. Then, inside the loop when you find a match, set it to 1 and break out of the loop:
userType=2
while IFS=, read -r ID name asignature final; do
if (( $ID == $user )); then
userType=1;
break
fi
done < notas.csv
You could also just use shell tools like awk:
userType=$(awk -F, -vtype=2 '($1=="'"$user"'") {type=1}; END {print type}' notas.csv)
or grep:
grep -q "^$user," notas.csv
userType=$(( $? + 1 ))
etc.
You should quote your variables in the if test statement. You should also perform a numeric test -eq rather than a string comparison =. So your if statement should look like:
if [[ "$ID" -eq "$user" ]]