I have a string 20000024ff3dbf50 that I would like to convert it like: 20:00:00:24:ff:3d:bf:50, I've tried with sed:
echo 20000024ff3dbf50 | sed 's/\(..\)\(..\)\(..\)\(..\)\(..\)\(..\)\(..\)\(..\)/\1:\2:\3:\4:\5:\6:\7:\8/'
but it's a little ugly.
Two substitutions:
echo "20000024ff3dbf50" | sed 's/../&:/g;s/.$//'
Results:
20:00:00:24:ff:3d:bf:50
echo 20000024ff3dbf50 | grep -o .. | paste -d ':' -s -
Grep with -o splits the input to 2 chars per line;
paste uses delimiter ':' to pad them [-s]erially
You could also use GNU awk auto-splitting for this:
echo 20000024ff3dbf50 | awk '$1=$1' FPAT=.. OFS=:
Output:
20:00:00:24:ff:3d:bf:50
Related
I was trying to filter all the files from the URLs and get only paths.
echo -e "http://sub.domain.tld/secured/database_connect.php\nhttp://sub.domain.tld/section/files/image.jpg\nhttp://sub.domain.tld/.git/audio-files/top-secret/audio.mp3" | grep -Ei "(http|https)://[^/\"]+" | sort -u
http://sub.domain.tld
But I want the result like this
http://sub.domain.tld/secured/
http://sub.domain.tld/section/files/
http://sub.domain.tld/.git/audio-files/top-secret/
Is there any way to do it with sed or grep
Using grep
$ echo ... | grep -o '.*/'
http://sub.domain.tld/secured/
http://sub.domain.tld/section/files/
http://sub.domain.tld/.git/audio-files/top-secret/
with grep
If your grep has the -o option:
... | grep -Eio 'https?://.*/'
If there could be multiple URLs per line:
... | grep -Eio 'https?://[^[:space:]]+/'
with sed
If the input is always precisely one URL per line and nothing else, you can just delete the filename part:
... | sed 's/[^/]*$//'
You could use match function of awk, will work in any version of awk. Simple explanation would be, passing echo command's output to awk program. Using match matching everything till last occurrence of / and then printing the sub-string to print just before /(with -1 to RLENGTH).
your_echo_command | awk 'match($0,/.*\//){print substr($0,RSTART,RLENGTH-1)}'
GNU Awk
$ echo ... | awk 'match($0,/.*\//,a){print a[0]}'
$ echo ... | awk '{print gensub(/(.*\/).*/,"\\1",1)}'
$ echo ... | awk 'sub(/[^/]*$/,"")'
http://sub.domain.tld/secured/
http://sub.domain.tld/section/files/
http://sub.domain.tld/.git/audio-files/top-secret/
xargs
$ echo ... | xargs -i sh -c 'echo $(dirname "{}")/'
http://sub.domain.tld/secured/
http://sub.domain.tld/section/files/
http://sub.domain.tld/.git/audio-files/top-secret/
I'm trying to get the count of a matching pattern from a variable to check the count of it, but it's only returning 1 as the results, here is what I'm trying to do:
x="HELLO|THIS|IS|TEST"
echo $x | grep -c "|"
Expected result: 3
Actual Result: 1
Do you know why is returning 1 instead of 3?
Thanks.
grep -c counts lines not matches within a line.
You can use awk to get a count:
x="HELLO|THIS|IS|TEST"
echo "$x" | awk -F '|' '{print NF-1}'
3
Alternatively you can use tr and wc:
echo "$x" | tr -dc '|' | wc -c
3
$ echo "$x" | grep -o '|' | grep -c .
3
grep -c does not count the number of matches. It counts the number of lines that match. By using grep -o, we put the matches on separate lines.
This approach works just as well with multiple lines:
$ cat file
hello|this|is
a|test
$ grep -o '|' file | grep -c .
3
The grep manual says:
grep, egrep, fgrep - print lines matching a pattern
and for the -c flag:
instead print a count of matching lines for each input file
and there is just one line that match
You don't need grep for this.
pipe_only=${x//[^|]} # remove everything except | from the value of x
echo "${#pipe_only}" # output the length of pipe_only
Try this :
$ x="HELLO|THIS|IS|TEST"; echo -n "$x" | sed 's/[^|]//g' | wc -c
3
With only one pipe with perl:
echo "$x" |
perl -lne 'print scalar(() = /\|/g)'
I'm trying to make a small function that removes all the chars that are not digits.
123a45a ---> will become ---> 12345
I've came up with :
temp=$word | grep -o [[:digit:]]
echo $temp
But instead of 12345 I get 1 2 3 4 5. How to I get rid of the spaces?
Pure bash:
word=123a45a
number=${word//[^0-9]}
Here's a pure bash solution
var='123a45a'
echo ${var//[^0-9]/}
12345
is this what you are looking for?
kent$ echo "123a45a"|sed 's/[^0-9]//g'
12345
grep & tr
echo "123a45a"|grep -o '[0-9]'|tr -d '\n'
12345
I would recommend using sed or perl instead:
temp="$(sed -e 's/[^0-9]//g' <<< "$word")"
temp="$(perl -pe 's/\D//g' <<< "$word")"
Edited to add: If you really need to use grep, then this is the only way I can think of:
temp="$( grep -o '[0-9]' <<< "$word" \
| while IFS= read -r ; do echo -n "$REPLY" ; done
)"
. . . but there's probably a better way. (It uses grep -o, like your solution, then runs over the lines that it outputs and re-outputs them without line-breaks.)
Edited again to add: Now that you've mentioned that you use can use tr instead, this is much easier:
temp="$(tr -cd 0-9 <<< "$word")"
What about using sed?
$ echo "123a45a" | sed -r 's/[^0-9]//g'
12345
As I read you are just allowed to use grep and tr, this can make the trick:
$ echo "123a45a" | grep -o [[:digit:]] | tr -d '\n'
12345
In your case,
temp=$(echo $word | grep -o [[:digit:]] | tr -d '\n')
tr will also work:
echo "123a45a" | tr -cd '[:digit:]'
# output: 12345
Grep returns the result on different lines:
$ echo -e "$temp"
1
2
3
4
5
So you cannot remove those spaces during the filtering, but you can afterwards, since $temp can transform itself like this:
temp=`echo $temp | tr -d ' '`
$ echo "$temp"
12345
I have an application (myapp) that gives me a multiline output
result:
abc|myparam1|def
ghi|myparam2|jkl
mno|myparam3|pqr
stu|myparam4|vwx
With grep and sed I can get my parameters as below
myapp | grep '|' | sed -e 's/^[^|]*//' | sed -e 's/|.*//'
But then want these myparamx values as paramaters of a script to be executed for each parameter.
myscript.sh myparam1
myscript.sh myparam2
etc.
Any help greatly appreciated
Please see xargs. For example:
myapp | grep '|' | sed -e 's/^[^|]*//' | sed -e 's/|.*//' | xargs -n 1 myscript.sh
May be this can help -
myapp | awk -F"|" '{ print $2 }' | while read -r line; do /path/to/script/ "$line"; done
I like the xargs -n 1 solution from Dark Falcon, and while read is a classical tool for such kind of things, but just for completeness:
myapp | awk -F'|' '{print "myscript.sh", $2}' | bash
As a side note, speaking about extraction of 2nd field, you could use cut:
myapp | cut -d'|' -f 1 # -f 1 => second field, starting from 0
Suppose I have the string 1:2:3:4:5 and I want to get its last field (5 in this case). How do I do that using Bash? I tried cut, but I don't know how to specify the last field with -f.
You can use string operators:
$ foo=1:2:3:4:5
$ echo ${foo##*:}
5
This trims everything from the front until a ':', greedily.
${foo <-- from variable foo
## <-- greedy front trim
* <-- matches anything
: <-- until the last ':'
}
Another way is to reverse before and after cut:
$ echo ab:cd:ef | rev | cut -d: -f1 | rev
ef
This makes it very easy to get the last but one field, or any range of fields numbered from the end.
It's difficult to get the last field using cut, but here are some solutions in awk and perl
echo 1:2:3:4:5 | awk -F: '{print $NF}'
echo 1:2:3:4:5 | perl -F: -wane 'print $F[-1]'
Assuming fairly simple usage (no escaping of the delimiter, for example), you can use grep:
$ echo "1:2:3:4:5" | grep -oE "[^:]+$"
5
Breakdown - find all the characters not the delimiter ([^:]) at the end of the line ($). -o only prints the matching part.
You could try something like this if you want to use cut:
echo "1:2:3:4:5" | cut -d ":" -f5
You can also use grep try like this :
echo " 1:2:3:4:5" | grep -o '[^:]*$'
One way:
var1="1:2:3:4:5"
var2=${var1##*:}
Another, using an array:
var1="1:2:3:4:5"
saveIFS=$IFS
IFS=":"
var2=($var1)
IFS=$saveIFS
var2=${var2[#]: -1}
Yet another with an array:
var1="1:2:3:4:5"
saveIFS=$IFS
IFS=":"
var2=($var1)
IFS=$saveIFS
count=${#var2[#]}
var2=${var2[$count-1]}
Using Bash (version >= 3.2) regular expressions:
var1="1:2:3:4:5"
[[ $var1 =~ :([^:]*)$ ]]
var2=${BASH_REMATCH[1]}
$ echo "a b c d e" | tr ' ' '\n' | tail -1
e
Simply translate the delimiter into a newline and choose the last entry with tail -1.
Using sed:
$ echo '1:2:3:4:5' | sed 's/.*://' # => 5
$ echo '' | sed 's/.*://' # => (empty)
$ echo ':' | sed 's/.*://' # => (empty)
$ echo ':b' | sed 's/.*://' # => b
$ echo '::c' | sed 's/.*://' # => c
$ echo 'a' | sed 's/.*://' # => a
$ echo 'a:' | sed 's/.*://' # => (empty)
$ echo 'a:b' | sed 's/.*://' # => b
$ echo 'a::c' | sed 's/.*://' # => c
There are many good answers here, but still I want to share this one using basename :
basename $(echo "a:b:c:d:e" | tr ':' '/')
However it will fail if there are already some '/' in your string.
If slash / is your delimiter then you just have to (and should) use basename.
It's not the best answer but it just shows how you can be creative using bash commands.
If your last field is a single character, you could do this:
a="1:2:3:4:5"
echo ${a: -1}
echo ${a:(-1)}
Check string manipulation in bash.
Using Bash.
$ var1="1:2:3:4:0"
$ IFS=":"
$ set -- $var1
$ eval echo \$${#}
0
echo "a:b:c:d:e"|xargs -d : -n1|tail -1
First use xargs split it using ":",-n1 means every line only have one part.Then,pring the last part.
Regex matching in sed is greedy (always goes to the last occurrence), which you can use to your advantage here:
$ foo=1:2:3:4:5
$ echo ${foo} | sed "s/.*://"
5
A solution using the read builtin:
IFS=':' read -a fields <<< "1:2:3:4:5"
echo "${fields[4]}"
Or, to make it more generic:
echo "${fields[-1]}" # prints the last item
for x in `echo $str | tr ";" "\n"`; do echo $x; done
improving from #mateusz-piotrowski and #user3133260 answer,
echo "a:b:c:d::e:: ::" | tr ':' ' ' | xargs | tr ' ' '\n' | tail -1
first, tr ':' ' ' -> replace ':' with whitespace
then, trim with xargs
after that, tr ' ' '\n' -> replace remained whitespace to newline
lastly, tail -1 -> get the last string
For those that comfortable with Python, https://github.com/Russell91/pythonpy is a nice choice to solve this problem.
$ echo "a:b:c:d:e" | py -x 'x.split(":")[-1]'
From the pythonpy help: -x treat each row of stdin as x.
With that tool, it is easy to write python code that gets applied to the input.
Edit (Dec 2020):
Pythonpy is no longer online.
Here is an alternative:
$ echo "a:b:c:d:e" | python -c 'import sys; sys.stdout.write(sys.stdin.read().split(":")[-1])'
it contains more boilerplate code (i.e. sys.stdout.read/write) but requires only std libraries from python.