So I have some code where I'm trying to only do the while loop if the first character of a string isn't or is a certain character.
while IFS=$'\t' read -r -a myArray
do
like=${myArray[0]}
position=${myArray[1]}
while [ ${like:0:1}=="E" ]
file=$like."Rput"
echo "$file"
So when I echo the file, the file name is ##file.output which is a file that I do not want at all. In the sense, I want it to completely skip it.
Could someone tell me what's going on?
Thanks!
It works if while is replaced with an if-then statement:
while IFS=$'\t' read -r -a myArray
do
like=${myArray[0]}
position=${myArray[1]}
if [ "${like:0:1}" == "E" ]
then
file=$like."Rput"
echo "$file"
fi
done
Note also that spaces are important. The following tests first character of like for equality with E:
[ "${like:0:1}" == "E" ]
But, the following does something unrelated:
[ "${like:0:1}"=="E" ]
Since the equal sign here is not separated by spaces, "${like:0:1}"=="E" is interpreted simply as a single string. Tests of a single string return true if the string is nonempty and false if it is empty. Since ${like:0:1}"=="E" is always non-empty, it will always return true.
Related
I need help to find the appropriate way to write my conditional statement because it is not working.
cumonth= date +%m
cudinamic=
if [ $cumonth =10 ];
then
cudinamic=a
elif [ $cumonth =11];
then
cudinamic=b
elif [ $cumonth =12];
then
cudinamic=c
else
cudinamic=$cumonth
fi
#Echo display message
$echo $ytday
$echo $cmonth
echo "$cudinamic"
To save the output of a command, use command substitution $(...):
cumonth=$(date +%m)
The arguments to [ must be separated by spaces, spaces aren't optional:
elif [ "$cumonth" = 11 ];
Note that there are 4 parameters: "$cumonth", =, 11, and ]. It's a good habit to quote the variable, in case it's empty or contains spaces, it will still be considered a single word.
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.
I'm using .conf which contain keys and values.
Some keys contains numbers like
deployment.conf
EAR_COUNT=2
EAR_1=xxx.ear
EAR_2=yyy.ear
When I try to retrieve that value using particular key and compare with integer value i.e. natural number.
But Whatever I retrieved values from .conf ,it is should be String datatype.
How should I compare both value in Linux Bash script.
Simply : How should I compare two values in Linux.?
Ex :
. ./deployment.conf
count=$EAR_COUNT;
echo "count : $count";
if [ $count -gt 0 ]; then
echo "Test"
fi
I'm getting following error :
count : 2
: integer expression expected30: [: 2
They're all strings in bash, notwithstanding your ability to do typeset-type things to flag them differently.
If you want to do numeric comparisons, just use -eq (or its brethren like -gt, -le) rather than ==, != and so on:
if [[ $num -eq 42 ]] ; then
echo Found the answer
fi
The full range of comparison operators can be found in the bash manpage, under CONDITIONAL EXPRESSIONS.
If you have something that you think should be a number and it's not working, I'll warrant it's not a number. Do something like:
echo "[$count]"
to make sure it doesn't have a newline at the end or, better yet, get a hex dump of it in case it holds strange characters, like Windows line endings:
echo -n $count | od -xcb
The fact that you're seeing:
: integer expression expected30: [: 2
with the : back at the start of the line, rather than the more usual:
-bash: [: XX: integer expression expected
tends to indicate the presence of a carriage return in there, which might be from deployment.conf having those Windows line endings (\r\n rather than the UNIXy \n).
The hex dump should make that obvious, at which point you need to go and clean up your configuration file.
Ref : http://linux.die.net/man/1/bash
-eq, -ne, -lt, -le, -gt, or -ge
These are arithmetic binary operators in bash scripting.
I have checked your code,
deployment.conf
# CONF FILE
EAR_COUNT=5
testArithmetic.sh
#!/bin/bash
. ./deployment.conf
count=$EAR_COUNT;
echo "count : $count";
if [ $count -gt 0 ]; then
echo "Test"
fi
running the above script evaluates to numeric comparison for fine. Share us your conf file contents, if you are facing any issues. If you are including the conf file in your script file, note the conf file must have valid BASH assignments, which means, there should be no space before and after '=' sign.
Also, you have mentioned WAR_COUNT=3 in conf part and used 'count=$EAR_COUNT;' in script part. Please check this too.
Most likely you have some non-integer character like \r in your EAR_COUNT variable. Strip all non-digits while assigning to count like this:
count=${EAR_COUNT//[^[:digit:]]/}
echo "count : $count";
if [[ $count -gt 0 ]]; then
echo "Test"
fi
I'm having trouble getting grep to work properly in an if statement. In the following code segment, the if-check always comes up true (i.e. the word is not found), and the program prints NOT FOUND, even though the words are already in ~/.memory.
for (( i=0; i<${#aspellwords[*]}; i++)); do
if [ !$(grep -q "${aspellwords[$i]}" ~/.memory) ]; then
words[$i]="${aspellwords[$i]}"
printf "\nNOT FOUND\n"
fi
done
However, when I test the following code in place of the previous segment:
for (( i=0; i<${#aspellwords[*]}; i++)); do
if grep -q "${aspellwords[$i]}" ~/.memory; then echo FOUND IT; fi
done
It works perfectly fine and finds the word without any issues.
So what's wrong with the first segment of code?
A number of things are wrong with that first snippet.
You don't want [ ... ] if you want to test the return code. Drop those.
[] is not part of the if syntax (as you can see from your second snippet).
[ is a shell built-in and binary on your system. It just exits with a return code. if ...; then tests the return code of ....
$() is command substitution. It replaces itself with the output from the command that was run.
So [ !$(grep ...) ] is actually evaluating [ !output_from_grep ] and [ word ] is interpreted as [ -n word ] which will be true whenever word is non-empty. Given that ! is never non-empty that will always be true.
Simply, as indicated by #thom in his comment (a bit obliquely), add the ! negation to your second snippet with a space between it and grep.
The following code gives
[: -ge: unary operator expected
when
i=0
if [ $i -ge 2 ]
then
#some code
fi
why?
Your problem arises from the fact that $i has a blank value when your statement fails. Always quote your variables when performing comparisons if there is the slightest chance that one of them may be empty, e.g.:
if [ "$i" -ge 2 ] ; then
...
fi
This is because of how the shell treats variables. Assume the original example,
if [ $i -ge 2 ] ; then ...
The first thing that the shell does when executing that particular line of code is substitute the value of $i, just like your favorite editor's search & replace function would. So assume that $i is empty or, even more illustrative, assume that $i is a bunch of spaces! The shell will replace $i as follows:
if [ -ge 2 ] ; then ...
Now that variable substitutions are done, the shell proceeds with the comparison and.... fails because it cannot see anything intelligible to the left of -gt. However, quoting $i:
if [ "$i" -ge 2 ] ; then ...
becomes:
if [ " " -ge 2 ] ; then ...
The shell now sees the double-quotes, and knows that you are actually comparing four blanks to 2 and will skip the if.
You also have the option of specifying a default value for $i if $i is blank, as follows:
if [ "${i:-0}" -ge 2 ] ; then ...
This will substitute the value 0 instead of $i is $i is undefined. I still maintain the quotes because, again, if $i is a bunch of blanks then it does not count as undefined, it will not be replaced with 0, and you will run into the problem once again.
Please read this when you have the time. The shell is treated like a black box by many, but it operates with very few and very simple rules - once you are aware of what those rules are (one of them being how variables work in the shell, as explained above) the shell will have no more secrets for you.
Judging from the error message the value of i was the empty string when you executed it, not 0.
I need to add my 5 cents. I see everybody use [ or [[, but it worth to mention that they are not part of if syntax.
For arithmetic comparisons, use ((...)) instead.
((...)) is an arithmetic command, which returns an exit status of 0 if
the expression is nonzero, or 1 if the expression is zero. Also used
as a synonym for "let", if side effects (assignments) are needed.
See: ArithmeticExpression
Your piece of script works just great. Are you sure you are not assigning anything else before the if to "i"?
A common mistake is also not to leave a space after and before the square brackets.