Remove root directory from filename in linux - linux

I want to split this line
/home/edwprod/abortive_visit/bin/abortive_proc_call.ksh
to
/edwprod/abortive_visit/bin/abortive_proc_call.ksh
Can I use sed or awk command for this?

you don't need awk or sed , just try this
echo -n "/"; echo "/home/edwprod/abortive_visit/bin/abortive_proc_call.ksh" |cut -f3-6 -d/

echo '/home/edwprod/abortive_visit/bin/abortive_proc_call.ksh' | sed 's#^/[^/]\+##'
Explanatory words: using sed's replace function, we redefine the separator, which is commonly /, to #, saving us the escaping of slashes within the string. We anchor the regex at the beginning of line ^, and replace the first slash, followed by any non-slash, with nothing, thus removing the first element of the path (not the root, btw).

Related

Linux Bash. Delete line if field exactly matches

I have something like this in a file named file.txt
AA.201610.pancake.Paul
AA.201610.hello.Robert
A.201610.hello.Mark
Now, i ONLY get the first three fields in 3 variables like:
field1="A"
field2="201610"
field3='hello'.
I'd like to remove a line, if it contains exactly the first 3 fields, like , in the case described above, i want only the third line to be removed from the file.txt . Is there a way to do that? And is there a way to do that in the same file?
I tried with:
sed -i /$field1"."$field2"."$field3"."/Id file.txt
but of course this removes both the second and the third line
I suggest using awk for this as sed can only do regex search and that requires escaping all special meta-chars and anchors, word boundaries etc to avoid false matches.
Suggested awk with non-regex matching:
awk -F '[.]' -v f1="$field1" -v f2="$field2" -v f3="$field3" '
!($1==f1 && $2==f2 && $3==f3)' file
AA.201610.pancake.Paul
AA.201610.hello.Robert
Use ^ to anchor the pattern at the beginning of the line. Also note that . in a regex means "any character" and not a literal peridio. You have to escape it: either \. (be careful with shell escaping and the difference between single and double quotes) or [.]
Sed cannot do string matches, only regexp matches which becomes horrendously complicated to work around when you simply want to match a literal string (see Is it possible to escape regex metacharacters reliably with sed). Just use awk:
$ awk -v str="${field1}.${field2}.${field3}." 'index($0,str)!=1' file
AA.201610.pancake.Paul
AA.201610.hello.Robert
The question was about bash so in bash:
#!/usr/bin/env bash
field1="A"
field2="201610"
field3='hello'
IFS=
while read -r i
do
case "$i" in
"${field1}.${field2}.${field3}."*) ;;
*) echo -E "$i"
esac
done < file.txt

How cut characters from string and put it at the end- In shell

I want to be able to do the following:
String1= "HELLO 3002_3322 3.2.1.log"
And get output like:
output = "3002_3322 3.2.1.log HELLO"
I know the command sed is able to do this but I need some guidance.
Thanks!
AWK
awk is one tool to do something like that:
echo "HELLO 3002_3322 3.2.1.log" | awk '{print $2$3" "$1}'
What it does:
awk, without delimiter flag of -F splits by whitespace sequences
that means, HELLO 3002_3322 and 3.2.1.log will be seen
HELLO is referred to by $1; 3002_3322 is $2 and so on
we print $2, then $3 then one space, then $1
SED
I have a unpretty looking sed example for you:
echo "HELLO 3002_3322 3.2.1.log" | sed 's_\(.*\)\s\(.*\)\s\(.*\)_\3 \2 \1_'
What it does:
nomenclature is s_<pattern>_<replacement>_
first s stands for substitute
_ is the delimiter
(.*) is paranthesis dot star parenthesis. That is the first group of characters we are asking sed to match. .* means match any sequence of characters or no characters at all. Ignore the \ before ( and ) for now
Notice the \s after the group. \s matches one space. So, we are asking sed to separate out (.*)\s - i.e. ()
We repeat that to tell sed - (group1)(group2)(group3)
First group's shorthand is \1, group2's shorthand is \2 etc.
For replacement, we tell sed to arrange \3 (group3) first, then \2 (group2) and then \1 (group1)
( is a special character in sed. So we have to escape it by a forward slash. So, (.*)\s(.*)\s(.*) becomes \(.*\)\s\(.*\)\s\(.*\). Oh so pretty!
In sed you can do:
sed 's/\([^[:blank:]]*\)[[:blank:]]*\(.*\)/\2 \1/'
Which outputs 3002_3322 3.2.1.log HELLO.
Explanation
The first word is captured by
\([^[:blank:]]*\)
The \(\) means I want to capture this group to use later. [:blank:] is a POSIX character class for whitespace characters. You can see the other POSIX character classes here:
http://www.regular-expressions.info/posixbrackets.html
The outer [] means match anyone of the characters, and the ^ means any character except those listed in the character class. Finally the * means any number of occurrences (including 0) of the previous character. So in total [^[:blank:]]* this means match a group of characters that are not whitespace, or the first word. We have to do this somewhat complicated regex because POSIX sed only supports BRE (basic regex) which is greedy matching, and to find the first word we want non-greedy matching.
[[:blank:]]*, as explained above, this means match a group of consecutive whitespaces.
\(.*\) This means capture the rest of the line. The . means any single character, so combined with the * it means match the rest of the characters.
For the replacement, the \2 \1 means replace the pattern we matched with the 2nd capture group, a space, then the first capture group.
This might work for you (GNU sed):
sed -r 's/^(\S+)(\s+)(.*)/\3\2\1/' file
Pattern match non-spaces, spaces and what is left and then use the remembered patterns (back references) in the replacement part of the substitution command.
N.B. The -r aurgument just removes the need for copius back slashes, so the same solution may be written as:
sed 's/^\(\S\S*\)\(\s\s*\)\(.*\)/\3\2\1/' file
This also removes the syntatic sugar of the the metacharacter + which means one or more of the preceeding pattern.
Further note, that \S and \s may be replaced by [^[:space:]] and [[:space:]] respectively. Leading to:
sed 's/^\([^[:space:]][^[:space:]]*\)\([[:space:]][[:space:]]*\)\(.*\)/\3\2\1/' file
You can do this too (without awk or sed):
#!/bin/sh
String1="HELLO 3002_3322 3.2.1.log"
start="${String1%% *}"
end="${String1#* }"
output="$end $start"
echo "$output"
Or using cut (in Bash):
#!/bin/bash
String1="HELLO 3002_3322 3.2.1.log"
rstr="$(echo "$String1" |cut -d" " -f1)"
output="${String1/$rstr /} $rstr"
echo "$output"

A good way to use sed to find and replace characters with 2 delimiters

I trying to find and replace items using bash. I was able to use sed to grab out some of the characters, but I think I might be using it in the wrong matter.
I am basically trying to remove the characters after ";" and before "," including removing ","
sed -e 's/\(;\).*\(,\)/\1\2/'
That is what I used to replace it with nothing. However, it ends up replacing everything in the middle so my output came out like this:
cmd2="BMC,./socflash_x64 if=B600G3_BMC_V0207.ima;,reboot -f"
This is the original text of what I need to replace
cmd2="BMC,./socflash_x64 if=B600G3_BMC_V0207.ima;X,sleep 120;after_BMC,./run-after-bmc-update.sh;hba_fw,./hba_fw.sh;X,sleep 5;DB,2;X,reboot -f"
Is there any way to make it look like this output?
./socflash_x64 if=B600G3_BMC_V0207.ima;sleep 120;./run-after-bmc-update.sh;./hba_fw.sh;sleep 5;reboot -f
Ff there is any way to make this happen other than bash I am fine with any type of language.
Non-greedy search can (mostly) be simulated in programs that don't support it by replacing match-any (dot .) with a negated character class.
Your original command is
sed -e 's/\(;\).*\(,\)/\1\2/'
You want to match everything in between the semi-colon and the comma, but not another comma (non-greedy). Replace .* with [^,]*
sed -e 's/\(;\)[^,]*\(,\)/\1\2/'
You may also want to exclude semi-colons themselves, making the expression
sed -e 's/\(;\)[^,;]*\(,\)/\1\2/'
Note this would treat a string like "asdf;zxcv;1234,qwer" differently, since one would match ;zxcv;1234, and the other would match only ;1234,
In perl:
perl -pe 's/;.*?,/;/g;' -pe 's/^[^,]*,//' foo.txt
will output:
./socflash_x64 if=B600G3_BMC_V0207.ima;sleep 120;./run-after-bmc-update.sh;./hba_fw.sh;sleep 5;2;reboot -f
The .*? is non greedy matching before the comma. The second command is to remove from the beginning to the comma.
Something like:
echo $cmd2 | tr ';' '\n' | cut -d',' -f2- | tr '\n' ';' ; echo
result is:
./socflash_x64 if=B600G3_BMC_V0207.ima;sleep 120;./run-after-bmc-update.sh;./hba_fw.sh;sleep 5;2;reboot -f;
however, I thing your requirements are a few more complex, because 'DB,2' seems a particular case. After "tr" command, insert a "grep" or "grep -v" to include/exclude these cases.

Bash script to remove 'x' amount of characters the end of multiple filenames in a directory?

I have a list of file names in a directory (/path/to/local). I would like to remove a certain number of characters from all of those filenames.
Example filenames:
iso1111_plane001_00321.moc1
iso1111_plane002_00321.moc1
iso2222_plane001_00123.moc1
In every filename I wish to remove the last 5 characters before the file extension.
For example:
iso1111_plane001_.moc1
iso1111_plane002_.moc1
iso2222_plane001_.moc1
I believe this can be done using sed, but I cannot determine the exact coding. Something like...
for filename in /path/to/local/*.moc1; do
mv $filname $(echo $filename | sed -e 's/.....^//');
done
...but that does not work. Sorry if I butchered the sed options, I do not have much experience with it.
mv $filname $(echo $filename | sed -e 's/.....\.moc1$//');
or
echo ${filename%%?????.moc1}.moc1
%% is a bash internal operator...
This sed command will work for all the examples you gave.
sed -e 's/\(.*\)_.*\.moc1/\1_.moc1/'
However, if you just want to specifically "remove 5 characters before the last extension in a filename" this command is what you want:
sed -e 's/\(.*\)[0-9a-zA-Z]\{5\}\.\([^.]*\)/\1.\2/'
You can implement this in your script like so:
for filename in /path/to/local/*.moc1; do
mv $filename "$(echo $filename | sed -e 's/\(.*\)[0-9a-zA-Z]\{5\}\.\([^.]*\)/\1.\2/')";
done
First Command Explanation
The first sed command works by grabbing all characters until the first underscore: \(.*\)_
Then it discards all characters until it finds .moc1: .*\.moc1
Then it replaces the text that it found with everything it grabbed at first inside the parenthesis: /\1
And finally adds the .moc1 extension back on the end and ends the regex: .moc1/
Second Command Explanation
The second sed command works by grabbing all characters at first: \(.*\)
And then it is forced to stop grabbing characters so it can discard five characters, or more specifically, five characters that lie in the ranges 0-9, a-z, and A-Z: [0-9a-zA-Z]\{5\}
Then comes the dot '.' character to mark the last extension : \.
And then it looks for all non-dot characters. This ensures that we are grabbing the last extension: \([^.]*\)
Finally, it replaces all that text with the first and second capture groups, separated by the . character, and ends the regex: /\1.\2/
This might work for you (GNU sed):
sed -r 's/(.*).{5}\./\1./' file

Environment variable substitution in sed

If I run these commands from a script:
#my.sh
PWD=bla
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
xxx
bla
it is fine.
But, if I run:
#my.sh
sed 's/xxx/'$PWD'/'
...
$ ./my.sh
$ sed: -e expression #1, char 8: Unknown option to `s'
I read in tutorials that to substitute environment variables from shell you need to stop, and 'out quote' the $varname part so that it is not substituted directly, which is what I did, and which works only if the variable is defined immediately before.
How can I get sed to recognize a $var as an environment variable as it is defined in the shell?
Your two examples look identical, which makes problems hard to diagnose. Potential problems:
You may need double quotes, as in sed 's/xxx/'"$PWD"'/'
$PWD may contain a slash, in which case you need to find a character not contained in $PWD to use as a delimiter.
To nail both issues at once, perhaps
sed 's#xxx#'"$PWD"'#'
In addition to Norman Ramsey's answer, I'd like to add that you can double-quote the entire string (which may make the statement more readable and less error prone).
So if you want to search for 'foo' and replace it with the content of $BAR, you can enclose the sed command in double-quotes.
sed 's/foo/$BAR/g'
sed "s/foo/$BAR/g"
In the first, $BAR will not expand correctly while in the second $BAR will expand correctly.
Another easy alternative:
Since $PWD will usually contain a slash /, use | instead of / for the sed statement:
sed -e "s|xxx|$PWD|"
You can use other characters besides "/" in substitution:
sed "s#$1#$2#g" -i FILE
一. bad way: change delimiter
sed 's/xxx/'"$PWD"'/'
sed 's:xxx:'"$PWD"':'
sed 's#xxx#'"$PWD"'#'
maybe those not the final answer,
you can not known what character will occur in $PWD, / : OR #.
if delimiter char in $PWD, they will break the expression
the good way is replace(escape) the special character in $PWD.
二. good way: escape delimiter
for example:
try to replace URL as $url (has : / in content)
x.com:80/aa/bb/aa.js
in string $tmp
URL
A. use / as delimiter
escape / as \/ in var (before use in sed expression)
## step 1: try escape
echo ${url//\//\\/}
x.com:80\/aa\/bb\/aa.js #escape fine
echo ${url//\//\/}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//\//\/}"
x.com:80\/aa\/bb\/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s/URL/${url//\//\\/}/"
URL
echo $tmp | sed "s/URL/${url//\//\/}/"
URL
OR
B. use : as delimiter (more readable than /)
escape : as \: in var (before use in sed expression)
## step 1: try escape
echo ${url//:/\:}
x.com:80/aa/bb/aa.js #escape not success
echo "${url//:/\:}"
x.com\:80/aa/bb/aa.js #escape fine, notice `"`
## step 2: do sed
echo $tmp | sed "s:URL:${url//:/\:}:g"
x.com:80/aa/bb/aa.js
With your question edit, I see your problem. Let's say the current directory is /home/yourname ... in this case, your command below:
sed 's/xxx/'$PWD'/'
will be expanded to
sed `s/xxx//home/yourname//
which is not valid. You need to put a \ character in front of each / in your $PWD if you want to do this.
Actually, the simplest thing (in GNU sed, at least) is to use a different separator for the sed substitution (s) command. So, instead of s/pattern/'$mypath'/ being expanded to s/pattern//my/path/, which will of course confuse the s command, use s!pattern!'$mypath'!, which will be expanded to s!pattern!/my/path!. I’ve used the bang (!) character (or use anything you like) which avoids the usual, but-by-no-means-your-only-choice forward slash as the separator.
Dealing with VARIABLES within sed
[root#gislab00207 ldom]# echo domainname: None > /tmp/1.txt
[root#gislab00207 ldom]# cat /tmp/1.txt
domainname: None
[root#gislab00207 ldom]# echo ${DOMAIN_NAME}
dcsw-79-98vm.us.oracle.com
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: ${DOMAIN_NAME}/g'
--- Below is the result -- very funny.
domainname: ${DOMAIN_NAME}
--- You need to single quote your variable like this ...
[root#gislab00207 ldom]# cat /tmp/1.txt | sed -e 's/domainname: None/domainname: '${DOMAIN_NAME}'/g'
--- The right result is below
domainname: dcsw-79-98vm.us.oracle.com
VAR=8675309
echo "abcde:jhdfj$jhbsfiy/.hghi$jh:12345:dgve::" |\
sed 's/:[0-9]*:/:'$VAR':/1'
where VAR contains what you want to replace the field with
I had similar problem, I had a list and I have to build a SQL script based on template (that contained #INPUT# as element to replace):
for i in LIST
do
awk "sub(/\#INPUT\#/,\"${i}\");" template.sql >> output
done
If your replacement string may contain other sed control characters, then a two-step substitution (first escaping the replacement string) may be what you want:
PWD='/a\1&b$_' # these are problematic for sed
PWD_ESC=$(printf '%s\n' "$PWD" | sed -e 's/[\/&]/\\&/g')
echo 'xxx' | sed "s/xxx/$PWD_ESC/" # now this works as expected
for me to replace some text against the value of an environment variable in a file with sed works only with quota as the following:
sed -i 's/original_value/'"$MY_ENVIRNONMENT_VARIABLE"'/g' myfile.txt
BUT when the value of MY_ENVIRONMENT_VARIABLE contains a URL (ie https://andreas.gr) then the above was not working.
THEN use different delimiter:
sed -i "s|original_value|$MY_ENVIRNONMENT_VARIABLE|g" myfile.txt

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