I'm developing a little script using ash shell (not bash).
Now i have a variable with the following composition:
VARIABLE = "number string status"
where number could be any number (actually between 1 and 18 but in the future that number could be higher) the string is a name and status is or on or off
The name usually is only lowercase letter.
Now my problem is to read only the string content in the variable, removing the number and the status.
How i can obtain that?
Two ways; one is to leverage $IFS and use a while loop - this will work for a single line quite happily - as:
echo "Part1 Part2 Part3" | while read a b c
do
echo $a
done
alternatively, use cut as follows:
a=`echo $var | cut -d' ' -f2`
echo $a
How about using cut?
name=$(echo "$variable" | cut -d " " -f 2)
UPDATE
Apparently, Ash doesn't understand $(...). Hopefully you can do this instead:
name=`echo "$variable" | cut -d " " -f 2`
How about :
name=$(echo "$variable" | awk '{print $2}')
#!/bin/sh
myvar="word1 word2 word3 wordX"
set -- $myvar
echo ${15} # outputs word 15
Related
I had problem with cut variables from string in " quotes. I have some scripts to write for my sys classes, I had a problem with a script in which I had to read input from the user in the form of (a="var1", b="var2")
I tried the code below
#!/bin/bash
read input
a=$($input | cut -d '"' -f3)
echo $a
it returns me a error "not found a command" on line 3 I tried to double brackets like
a=$(($input | cut -d '"' -f3)
but it's still wrong.
In a comment the OP gave a working answer (should post it as an answer):
#!/bin/bash
read input
a=$(echo $input | cut -d '"' -f2)
b=$(echo $input | cut -d '"' -f4)
echo sum: $(( a + b))
echo difference: $(( a - b))
This will work for user input that is exactly like a="8", b="5".
Never trust input.
You might want to add the check
if [[ ${input} =~ ^[a-z]+=\"[0-9]+\",\ [a-z]+=\"[0-9]+\"$ ]]; then
echo "Use your code"
else
echo "Incorrect input"
fi
And when you add a check, you might want to execute the input (after replacing the comma with a semicolon).
input='testa="8", testb="5"'
if [[ ${input} =~ ^[a-z]+=\"[0-9]+\",\ [a-z]+=\"[0-9]+\"$ ]];
then
eval $(tr "," ";" <<< ${input})
set | grep -E "^test[ab]="
else
echo no
fi
EDIT:
#PesaThe commented correctly about BASH_REMATCH:
When you use bash and a test on the input you can use
if [[ ${input} =~ ^[a-z]+=\"([0-9]+)\",\ [a-z]+=\"([0-9])+\"$ ]];
then
a="${BASH_REMATCH[1]}"
b="${BASH_REMATCH[2]}"
fi
To extract the digit 1 from a string "var1" you would use a Bash substring replacement most likely:
$ s="var1"
$ echo "${s//[^0-9]/}"
1
Or,
$ a="${s//[^0-9]/}"
$ echo "$a"
1
This works by replacing any non digits in a string with nothing. Which works in your example with a single number field in the string but may not be what you need if you have multiple number fields:
$ s2="1 and a 2 and 3"
$ echo "${s2//[^0-9]/}"
123
In this case, you would use sed or grep awk or a Bash regex to capture the individual number fields and keep them distinct:
$ echo "$s2" | grep -o -E '[[:digit:]]+'
1
2
3
I'm trying to print domain and topLeveldomain variables (example.com)
$line = example.com
domain =$line | cut -d. -f 1
topLeveldomain = $line | cut -d. -f 2
However when I try and echo $domain, it doesn't display desired value
test.sh: line 4: domain: command not found
test.sh: line 5: topLeveldomain: command not found
I suggest:
line="example.com"
domain=$(echo "$line" | cut -d. -f 1)
topLeveldomain=$(echo "$line" | cut -d. -f 2)
The right code for this should be:
line="example.com"
domain=$(echo "$line" | cut -d. -f 1)
topLeveldomain=$(echo "$line" | cut -d. -f 2)
Consider the right syntax of bash:
variable=value
(there are no blanks allowed)
if you want to use the content of the variable you have to add a leading $
e.g.
echo $variable
You don't need external tools for this, just do this in bash
$ string="example.com"
# print everything upto first de-limiter '.'
$ printf "${string%%.*}\n"
example
# print everything after first de-limiter '.'
$ printf "${string#*.}\n"
com
Remove spaces around =:
line=example.com # YES
line = example.com # NO
When you create a variable, do not prepend $ to the variable name:
line=example.com # YES
$line=example.com # NO
When using pipes, you need to pass standard output to the next command. Than means, you usually need to echo variables or cat files:
echo $line | cut -d. -f1 # YES
$line | cut -d. -f1 # NO
Use the $() syntax to get the output of a command into a variable:
new_variable=$(echo $line | cut -d. -f1) # YES
new_variable=echo $line | cut -d. -f1 # NO
I would rather use AWK:
domain="abc.def.hij.example.com"
awk -F. '{printf "TLD:%s\n2:%s\n3:%s\n", $NF, $(NF-1), $(NF-2)}' <<< "$domain"
Output
TLD:com
2:example
3:hij
In the command above, -F option specifies the field separator; NF is a built-in variable that keeps the number of input fields.
Issues with Your Code
The issues with your code are due to invalid syntax.
To set a variable in the shell, use
VARNAME="value"
Putting spaces around the equal sign will cause errors. It is a good
habit to quote content strings when assigning values to variables:
this will reduce the chance that you make errors.
Refer to the Bash Guide for Beginners.
this also works:
line="example.com"
domain=$(echo $line | cut -d. -f1)
toplevel=$(cut -d. -f2 <<<$line)
echo "domain name=" $domain
echo "Top Level=" $toplevel
You need to remove $ from line in the beginning, correct the spaces and echo $line in order to pipe the value to cut . Alternatively feed the cut with $line.
I am trying to run this command:
./smstocurl SLASH2.911325850268888.911325850268896
smstocurl script:
#SLASH2.911325850268888.911325850268896
model=$(echo \&model=$1 | cut -d'.' -f 1)
echo $model
imea1=$(echo \&simImea1=$1 | cut -d'.' -f 2)
echo $imea1
imea2=$(echo \&simImea2=$1 | cut -d'.' -f 3)
echo $imea2
echo $model$imea1$imea2
Result Received
&model=SLASH2911325850268888911325850268896
Result Expected
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
What am I missing here ?
You are cutting based on the dot .. In the first case your desired string contains the first string, the one containing &model, so then it is printed.
However, in the other cases you get the 2nd and 3rd blocks (-f2, -f3), so that the imea text gets cutted off.
Instead, I would use something like this:
while IFS="." read -r model imea1 imea2
do
printf "&model=%s&simImea1=%s&simImea2=%s\n" $model $imea1 $imea2
done <<< "$1"
Note the usage of printf and variables to have more control about what we are writing. Using a lot of escapes like in your echos can be risky.
Test
while IFS="." read -r model imea1 imea2; do printf "&model=%s&simImea1=%s&simImea2=%s\n" $model $imea1 $imea2
done <<< "SLASH2.911325850268888.911325850268896"
Returns:
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
Alternatively, this sed makes it:
sed -r 's/^([^.]*)\.([^.]*)\.([^.]*)$/\&model=\1\&simImea1=\2\&simImea2=\3/' <<< "$1"
by catching each block of words separated by dots and printing back.
You can also use this way
Run:
./program SLASH2.911325850268888.911325850268896
Script:
#!/bin/bash
String=`echo $1 | sed "s/\./\&simImea1=/"`
String=`echo $String | sed "s/\./\&simImea2=/"`
echo "&model=$String
Output:
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
awk way
awk -F. '{print "&model="$1"&simImea1="$2"&simImea2="$3}' <<< "SLASH2.911325850268888.911325850268896"
or
awk -F. '$0="&model="$1"&simImea1="$2"&simImea2="$3' <<< "SLASH2.911325850268888.911325850268896"
output
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
I have a String like this
//ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf
and want to get last part of
00000000957481f9-08d035805a5c94bf
Let's say you have
text="//ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf"
If you know the position, i.e. in this case the 9th, you can go with
echo "$text" | cut -d'/' -f9
However, if this is dynamic and your want to split at "/", it's safer to go with:
echo "${text##*/}"
This removes everything from the beginning to the last occurrence of "/" and should be the shortest form to do it.
For more information on this see: Bash Reference manual
For more information on cut see: cut man page
The tool basename does exactly that:
$ basename //ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf
00000000957481f9-08d035805a5c94bf
I would use bash string function:
$ string="//ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf"
$ echo "${string##*/}"
00000000957481f9-08d035805a5c94bf
But following are some other options:
$ awk -F'/' '$0=$NF' <<< "$string"
00000000957481f9-08d035805a5c94bf
$ sed 's#.*/##g' <<< "$string"
00000000957481f9-08d035805a5c94bf
Note: <<< is herestring notation. They do not create a subshell, however, they are NOT portable to POSIX sh (as implemented by shells such as ash or dash).
In case you want more than just the last part of the path,
you could do something like this:
echo $PWD | rev | cut -d'/' -f1-2 | rev
You can use this BASH regex:
s='//ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf'
[[ "$s" =~ [^/]+$ ]] && echo "${BASH_REMATCH[0]}"
00000000957481f9-08d035805a5c94bf
This can be done easily in awk:
string="//ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf"
echo "${string}" | awk -v FS="/" '{ print $NF }'
Use "/" as field separator and print the last field.
You can try this...
echo //ABC/REC/TLC/SC-prod/1f9/20/00000000957481f9-08d035805a5c94bf |awk -F "/" '{print $NF}'
Here is a script which reads words from the file replaced.txt and displays the output each word in each line, But I want to display all the outputs in a single line.
#!/bin/sh
echo
echo "Enter the word to be translated"
read a
IFS=" " # Set the field separator
set $a # Breaks the string into $1, $2, ...
for a # a for loop by default loop through $1, $2, ...
do
{
b= grep "$a" replaced.txt | cut -f 2 -d" "
}
done
Content of "replaced.txt" file is given below:
hllo HELLO
m AM
rshbh RISHABH
jn JAIN
hw HOW
ws WAS
ur YOUR
dy DAY
This question can't be appropriate to what I asked, I just need the help to put output of the script in a single line.
Your entire script can be replaced by:
#!/bin/bash
echo
read -r -p "Enter the words to be translated: " a
echo $(printf "%s\n" $a | grep -Ff - replaced.txt | cut -f 2 -d ' ')
No need for a loop.
The echo with an unquoted argument removes embedded newlines and replaces each sequence of multiple spaces and/or tabs with one space.
One hackish-but-simple way to remove trailing newlines from the output of a command is to wrap it in printf %s "$(...) ". That is, you can change this:
b= grep "$a" replaced.txt | cut -f 2 -d" "
to this:
printf %s "$(grep "$a" replaced.txt | cut -f 2 -d" ") "
and add an echo command after the loop completes.
The $(...) notation sets up a "command substitution": the command grep "$a" replaced.txt | cut -f 2 -d" " is run in a subshell, and its output, minus any trailing newlines, is substituted into the argument-list. So, for example, if the command outputs DAY, then the above is equivalent to this:
printf %s "DAY "
(The printf %s ... notation is equivalent to echo -n ... — it outputs a string without adding a trailing newline — except that its behavior is more portably consistent, and it won't misbehave if the string you want to print happens to start with -n or -e or whatnot.)
You can also use
awk 'BEGIN { OFS=": "; ORS=" "; } NF >= 2 { print $2; }'
in a pipe after the cut.