shell script counting semicolons in a string - shell

I wrote the following code as part of my project work. I need to print i value based on the number of ;(semi colons) in the input string. But the while loop is not getting executed. It is returning errors. I tried lot of alternatives but could not figure it out.
IN="aa;bb;cc;"
c= echo $IN | tr -dc ';' | wc -c
echo $c
i=1
while [ $i -le $c ];
do
echo $i
i=`expr $i + 1`
done

You need to change this:
c= echo $IN | tr -dc ';' | wc -c
to this:
c=`echo $IN | tr -dc ';' | wc -c`
so that echo $IN | tr -dc ';' | wc -c is run, and its output saved in c — just like you're already doing for i later in the script:
i=`expr $i + 1`

Well if you can use awk, it's much shorter and easier:
echo $IN | awk '{ print length(gensub("[^;]","","g",$0)) }'

There's no need for looping once you have a string of ;. The shell can count the characters in a variable for you with ${#variable}.
$ IN="aa;bb;cc;"
$ c=$(echo $IN | tr -dc ';')
$ echo ${#c}
3

Related

Extract data between delimiters from a Shell Script variable

I have this shell script variable, var. It keeps 3 entries separated by new line. From this variable var, I want to extract 2, and 0.078688. Just these two numbers.
var="USER_ID=2
# 0.078688
Suhas"
These are the code I tried:
echo "$var" | grep -o -P '(?<=\=).*(?=\n)' # For extracting 2
echo "$var" | awk -v FS="(# |\n)" '{print $2}' # For extracting 0.078688
None of the above working. What is the problem here? How to fix this ?
Just use tr alone for retaining the numerical digits, the dot (.) and the white-space and remove everything else.
tr -cd '0-9. ' <<<"$var"
2 0.078688
From the man page, of tr for usage of -c, -d flags,
tr [OPTION]... SET1 [SET2]
-c, -C, --complement
use the complement of SET1
-d, --delete
delete characters in SET1, do not translate
To store it in variables,
IFS=' ' read -r var1 var2 < <(tr -cd '0-9. ' <<<"$var")
printf "%s\n" "$var1"
2
printf "%s\n" "$var2"
2
0.078688
Or in an array as
IFS=' ' read -ra numArray < <(tr -cd '0-9. ' <<<"$var")
printf "%s\n" "${numArray[#]}"
2
0.078688
Note:- The -cd flags in tr are POSIX compliant and will work on any systems that has tr installed.
echo "$var" |grep -oP 'USER_ID=\K.*'
2
echo "$var" |grep -oP '# \K.*'
0.078688
Your solution is near to perfect, you need to chance \n to $ which represent end of line.
echo "$var" |awk -F'# ' '/#/{print $2}'
0.078688
echo "$var" |awk -F'=' '/USER_ID/{print $2}'
2
You can do it with pure bash using a regex:
#!/bin/bash
var="USER_ID=2
# 0.078688
Suhas"
[[ ${var} =~ =([0-9]+).*#[[:space:]]([0-9\.]+) ]] && result1="${BASH_REMATCH[1]}" && result2="${BASH_REMATCH[2]}"
echo "${result1}"
echo "${result2}"
With awk:
First value:
echo "$var" | grep 'USER_ID' | awk -F "=" '{print $2}'
Second value:
echo "$var" | grep '#' | awk '{print $2}'
Assuming this is the format of data as your sample
# For extracting 2
echo "$var" | sed -e '/.*=/!d' -e 's///'
echo "$var" | awk -F '=' 'NR==1{ print $2}'
# For extracting 0.078688
echo "$var" | sed -e '/.*#[[:blank:]]*/!d' -e 's///'
echo "$var" | awk -F '#' 'NR==2{ print $2}'

BASH: Remove newline for multiple commands

I need some help . I want the result will be
UP:N%:N%
but the current result is
UP:N%
:N%
this is the code.
#!/bin/bash
UP=$(pgrep mysql | wc -l);
if [ "$UP" -ne 1 ];
then
echo -n "DOWN"
else
echo -n "UP:"
fi
df -hl | grep 'sda1' | awk ' {percent+=$5;} END{print percent"%"}'| column -t && echo -n ":"
top -bn2 | grep "Cpu(s)" | \sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | \awk 'END{print 100 - $1"%"}'
You can use command substitution in your first sentence (notice you're creating a subshell in this way):
echo -n $(df -hl | grep 'sda1' | awk ' {percent+=$5;} END{print percent"%"}'| column -t ):

Wordcount list in bash

I am trying to count words in a list. This works :
echo "$list" | wc -w
But when I want to place this in a variable I get zero:
i="$lijst" | wc -w
echo i
Put your code inside $() or backticks , so that the code get parsed.
i=$(echo "$list" | wc -w)
echo "$i"

how to list file names into a function

I have a folder with a bunch of files, the files only have a url in it i.e
http://itunes.apple.com/us/app/keynote/id361285480?mt=8
Here is my code. How can I get it to do this for each url in each file?
var='{"object":"App","action":"scrape","args":{"itunes_url":"!!!!HERE!!!!"}}'
string=$(echo "$var" | sed -e 's/"/\\"/g')
string='{"request":"'"$string"'"}'
api="http://api.lewis.com"
output=$(curl -s -d "request=$string" "$api")
code=$(echo "$output" | tr '{', '\n' | sed -n "2p" | sed -e 's/:/ /' | awk '{print $2}')
if [ "${code:0:1}" -ne "2" ]; then
# :(
echo "Error: response code $code was returned, "
else
string=$(echo "$output" | tr '{', '\n' | sed -e '/"signature":\(.*\)/d;/"data":\(.*\)/d;/"signature":\(.*\)/d;/"code":\(.*\)/d' |sed -e 's/\\"//g;s/\\\\\\\//\//g;s/\\//g' | tr '}', '\n' | sed -e 's/"//' | sed '/^$/d')
echo "$string"
fi
use a for loop
for filename in folder/*; do
-- your code where you do something using $filename --
done
og if you prefer to give the filenames as arguments to the script then:
for filename do
-- your code where you do something using $filename --
done
then run your script followed by the files
./script.sh folder/*
You could do:
for file in *; do
for line in $(cat $file); do
# Stuff goes here
done
done
Or even just:
for line in $(cat *); do
# Stuff goes here
done

Get just the integer from wc in bash

Is there a way to get the integer that wc returns in bash?
Basically I want to write the line numbers and word counts to the screen after the file name.
output: filename linecount wordcount
Here is what I have so far:
files=\`ls`
for f in $files;
do
if [ ! -d $f ] #only print out information about files !directories
then
# some way of getting the wc integers into shell variables and then printing them
echo "$f $lines $words"
fi
done
Most simple answer ever:
wc < filename
Just:
wc -l < file_name
will do the job. But this output includes prefixed whitespace as wc right-aligns the number.
You can use the cut command to get just the first word of wc's output (which is the line or word count):
lines=`wc -l $f | cut -f1 -d' '`
words=`wc -w $f | cut -f1 -d' '`
wc $file | awk {'print "$4" "$2" "$1"'}
Adjust as necessary for your layout.
It's also nicer to use positive logic ("is a file") over negative ("not a directory")
[ -f $file ] && wc $file | awk {'print "$4" "$2" "$1"'}
Sometimes wc outputs in different formats in different platforms. For example:
In OS X:
$ echo aa | wc -l
1
In Centos:
$ echo aa | wc -l
1
So using only cut may not retrieve the number. Instead try tr to delete space characters:
$ echo aa | wc -l | tr -d ' '
The accepted/popular answers do not work on OSX.
Any of the following should be portable on bsd and linux.
wc -l < "$f" | tr -d ' '
OR
wc -l "$f" | tr -s ' ' | cut -d ' ' -f 2
OR
wc -l "$f" | awk '{print $1}'
If you redirect the filename into wc it omits the filename on output.
Bash:
read lines words characters <<< $(wc < filename)
or
read lines words characters <<EOF
$(wc < filename)
EOF
Instead of using for to iterate over the output of ls, do this:
for f in *
which will work if there are filenames that include spaces.
If you can't use globbing, you should pipe into a while read loop:
find ... | while read -r f
or use process substitution
while read -r f
do
something
done < <(find ...)
If the file is small you can afford calling wc twice, and use something like the following, which avoids piping into an extra process:
lines=$((`wc -l "$f"`))
words=$((`wc -w "$f"`))
The $((...)) is the Arithmetic Expansion of bash. It removes any whitespace from the output of wc in this case.
This solution makes more sense if you need either the linecount or the wordcount.
How about with sed?
wc -l /path/to/file.ext | sed 's/ *\([0-9]* \).*/\1/'
typeset -i a=$(wc -l fileName.dat | xargs echo | cut -d' ' -f1)
Try this for numeric result:
nlines=$( wc -l < $myfile )
Something like this may help:
#!/bin/bash
printf '%-10s %-10s %-10s\n' 'File' 'Lines' 'Words'
for fname in file_name_pattern*; {
[[ -d $fname ]] && continue
lines=0
words=()
while read -r line; do
((lines++))
words+=($line)
done < "$fname"
printf '%-10s %-10s %-10s\n' "$fname" "$lines" "${#words[#]}"
}
To (1) run wc once, and (2) not assign any superfluous variables, use
read lines words <<< $(wc < $f | awk '{ print $1, $2 }')
Full code:
for f in *
do
if [ ! -d $f ]
then
read lines words <<< $(wc < $f | awk '{ print $1, $2 }')
echo "$f $lines $words"
fi
done
Example output:
$ find . -maxdepth 1 -type f -exec wc {} \; # without formatting
1 2 27 ./CNAME
21 169 1065 ./LICENSE
33 130 961 ./README.md
86 215 2997 ./404.html
71 168 2579 ./index.html
21 21 478 ./sitemap.xml
$ # the above code
404.html 86 215
CNAME 1 2
index.html 71 168
LICENSE 21 169
README.md 33 130
sitemap.xml 21 21
Solutions proposed in the answered question doesn't work for Darwin kernels.
Please, consider following solutions that work for all UNIX systems:
print exactly the number of lines of a file:
wc -l < file.txt | xargs
print exactly the number of characters of a file:
wc -m < file.txt | xargs
print exactly the number of bytes of a file:
wc -c < file.txt | xargs
print exactly the number of words of a file:
wc -w < file.txt | xargs
There is a great solution with examples on stackoverflow here
I will copy the simplest solution here:
FOO="bar"
echo -n "$FOO" | wc -l | bc # "3"
Maybe these pages should be merged?
Try this:
wc `ls` | awk '{ LINE += $1; WC += $2 } END { print "lines: " LINE " words: " WC }'
It creates a line count, and word count (LINE and WC), and increase them with the values extracted from wc (using $1 for the first column's value and $2 for the second) and finally prints the results.
"Basically I want to write the line numbers and word counts to the screen after the file name."
answer=(`wc $f`)
echo -e"${answer[3]}
lines: ${answer[0]}
words: ${answer[1]}
bytes: ${answer[2]}"
Outputs :
myfile.txt
lines: 10
words: 20
bytes: 120
files=`ls`
echo "$files" | wc -l | perl -pe "s#^\s+##"
You have to use input redirection for wc:
number_of_lines=$(wc -l <myfile.txt)
respectively in your context
echo "$f $(wc -l <"$f") $(wc -w <"$f")"

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