I am using Ubuntu Linux and grepping info out of a file (lets say filename.log) and want to save the file using some of the info inside of (filename.log).
example:
The info in the (filename.log) has version_name and date.
When displaying this info on screen using cat it will display:
version_name=NAME
date=TODAY
I then want to save the file as NAME-TODAY.log and have no idea how to do this.
Any help will be appreciated
You can chain a bunch of basic linux commands with the pipe character |. Combined with a thing called command substitution (taking the output of a complex command, to use in another command. syntax: $(your command)) you can achieve what you want to do.
This is what I came up with, based on your question:
cp filename.log $(grep -E "(version_name=)|(date=)" filename.log | cut -f 2 -d = | tr '\n' '-' | rev | cut -c 2- | rev).log
So here I used cp, $(), grep, cut, tr and finally rev.
Since you said you had no idea where to start, let me walk you trough this oneliner:
cp - it is used to copy the filename.log file to a new file,
with the name based on the values of version_name and date (step 2 and up)
command substitution $() the entire command between the round brackets is 'resolved' before finishing the cp command in step 1. e.g. in your example it would be NAME-TODAY. notice the .log at the end outside of the round brackets to give it a proper file extension. The output of this command in your example will be NAME-TODAY.log
grep -E "(version_name=)|(date=)" grep with regexp flag -E to be able to do what we are doing. Matches any lines that contain version_name= OR date=. The expected output is:
version_name=NAME
date=TODAY
cut -f 2 -d = because I am not interested in version_name
, but instead in the value associated with that field, I use cut to split the line at the equals character = with the flag -d =. I then select the value behind the equals character (the second field) with the flag -f 2. The expected output is:
NAME
TODAY
tr '\n' '-' because grep outputs on multiple lines, I want to remove all new lines and replace them with a dash. Expected output:
NAME-TODAY-
rev | cut -c 2- | rev I am grouping these. rev reverses the word I have created. with cut -c 2- I cut away all characters starting from the second character of the reversed word. This is required because I replaced new lines with dashes and this means I now have NAME-TODAY-. Basicly this is just an extra step to remove the last dash. See expected outputs of each step:
-YADOT-EMAN
YADOT-EMAN
NAME-TODAY
remember this value is in the command substituion of step 2, so the end result will be:
cp filename.log NAME-TODAY.log
I manged to solve this by doing the following: grep filename.log > /tmp/file.info && filename=$(echo $(grep "version_name" /tmp/filename.info | cut -d " " -f 3)-$(grep "date" /tmp/filename.info | cut -d " " -f 3)-$filename.log
I have a list of more than 1000 files on the following format.
0521865417_roman_pottery_in_the_archaeological_record_2007.pdf
0521865476_power_politics_and_religion_in_timurid_iran_2007.pdf
0521865514_toward_a_theory_of_human_rights_religion_law_courts_2006.pdf
0521865522_i_was_wrong_the_meanings_of_apologies_2008.pdf
I am on Linux and want to change them as follows
2007_roman_pottery_in_the_archaeological_record.pdf
2007_power_politics_and_religion_in_timurid_iran.pdf
2006_toward_a_theory_of_human_rights_religion_law_courts.pdf
2008_i_was_wrong_the_meanings_of_apologies.pdf
Using rename and awk I managed to get
2007_roman_pottery_in_the_archaeological_record_2007.pdf
2007_power_politics_and_religion_in_timurid_iran_2007.pdf
2006_toward_a_theory_of_human_rights_religion_law_courts_2006.pdf
2008_i_was_wrong_the_meanings_of_apologies_2008.pdf
The remaining task is now to remove the last field that holds the year.
A solution that uses sed to generate the new names and the rename commands then pipes them to bash:
ls -1 | sed -r 's/[0-9]*_([A-Za-z_]*)_[a-z]{3}_([0-9]{4})\.pdf$/mv & \2_\1.pdf/g' | bash
A work around from where you left of...
echo 2007_roman_pottery_in_the_archaeological_record_2007.pdf | awk -F '_' '{$NF=""; OFS="_"; print substr($0, 0, length($0)-1)".pdf";}'
I want to remove all the logs except the current log and the log before that.
These log files are created after 20 minutes.So the files names are like
abc_23_19_10_3341.log
abc_23_19_30_3342.log
abc_23_19_50_3241.log
abc_23_20_10_3421.log
where 23 is today's date(might include yesterday's date also)
19 is the hour(7 o clock),10,30,50,10 are the minutes.
In this case i want i want to keep abc_23_20_10_3421.log which is the current log(which is currently being writen) and abc_23_19_50_3241.log(the previous one)
and remove the rest.
I got it to work by creating a folder,putting the first files in that folder and removing the files and then deleting it.But that's too long...
I also tried this
files_nodelete=`ls -t | head -n 2 | tr '\n' '|'`
rm *.txt | egrep -v "$files_nodelete"
but it didnt work.But if i put ls instead of rm it works.
I am an amateur in linux.So please suggest a simple idea..or a logic..xargs rm i tried but it didnt work.
Also read about mtime,but seems abit complicated since I am new to linux
Working on a solaris system
Try the logadm tool in Solaris, it might be the simplest way to rotate logs. If you just want to get things done, it will do it.
http://docs.oracle.com/cd/E23823_01/html/816-5166/logadm-1m.html
If you want a solution similar (but working) to your try this:
ls abc*.log | sort | head -n-2 | xargs rm
ls abc*.log: list all files, matching the pattern abc*.log
sort: sorts this list lexicographical (by name) from oldes to to newest logfile
head -n-2: return all but the last two entry in the list (you can give -n a negativ count too)
xargs rm: compose the rm command with the entries from stdin
If there are two or less files in the directory, this command will return an error like
rm: missing operand
and will not delete any files.
It is usually not a good idea to use ls to point to files. Some files may cause havoc (files which have a [Newline] or a weird character in their name are the usual exemples ....).
Using shell globs : Here is an interresting way : we count the files newer than the one we are about to remove!
pattern='abc*.log'
for i in $pattern ; do
[ -f "$i" ] || break ;
#determine if this is the most recent file, in the current directory
# [I add -maxdepth 1 to limit the find to only that directory, no subdirs]
if [ $(find . -maxdepth 1 -name "$pattern" -type f -newer "$i" -print0 | tr -cd '\000' | tr '\000' '+' | wc -c) -gt 1 ];
then
#there are 2 files more recent than $i that match the pattern
#we can delete $i
echo rm "$i" # remove the echo only when you are 100% sure that you want to delete all those files !
else
echo "$i is one of the 2 most recent files matching '${pattern}', I keep it"
fi
done
I only use the globbing mechanism to feed filenames to "find", and just use the terminating "0" of the -printf0 to count the outputed filenames (thus I have no problems with any special characters in those filenames, I just need to know how many files were outputted)
tr -cd "\000" will keep only the \000, ie the terminating NUL character outputed by print0. Then I translate each \000 to a single + character, and I count them with the wc -c. If I see 0, "$i" was the most recent file. If I see 1, "$i" was the one just a bit older (so the find sees only the most recent one). And if I see more than 1, it means the 2 files (mathching the pattern) that we want to keep are newer than "$i", so we can delete "$i"
I'm sure someone will step in with a better one, but the idea could be reused, I guess...
Thanks guyz for all the answers.
I found my answer
files=`ls -t *.txt | head -n 2 | tr '\n' '|' | rev |cut -c 2- |rev`
rm `ls -t | egrep -v "$files"`
Thank you for the help
I have a little error with a script I wrote in bash and I can't figure out what's I'm doing wrong
note that I'm using this script for thousands of calculations and this error happened only a few times (like 20 or so), but it still happened
What the script does is this: basically it takes in input a web page that I got from a site with the utility w3m and it counts all the occurrences of the words in it... After it orders them from the most common to the ones that occur only once
this is the code:
#!/bin/bash
# counts the numbers of words from specific sites #
# writes in a file the occurrences ordered from the most common #
touch check # file used to analyze the occurrences
touch distribution # final file ordered
page=$1 # the web page that needs to be analyzed
occurrences=$2 # temporary file for the occurrences
dictionary=$3 # dictionary used for another purpose (ignore this)
# write the words one by column
cat $page | tr -c [:alnum:] "\n" | sed '/^$/d' > check
# lopp to analyze the words
cat check | while read words
do
word=${words}
strlen=${#word}
# ignores blacklisted words or small ones
if ! grep -Fxq $word .blacklist && [ $strlen -gt 2 ]
then
# if the word isn't in the file
if [ `egrep -c -i "^$word: " $occurrences` -eq 0 ]
then
echo "$word: 1" | cat >> $occurrences
# else if it is already in the file, it calculates the occurrences
else
old=`awk -v words=$word -F": " '$1==words { print $2 }' $occurrences`
### HERE IS THE ERROR, EITHER THE LET OR THE SED ###
let "new=old+1"
sed -i "s/^$word: $old$/$word: $new/g" $occurrences
fi
fi
done
# orders the words
awk -F": " '{print $2" "$1}' $occurrences | sort -rn | awk -F" " '{print $2": "$1}' > distribution
# ignore this, not important
grep -w "1" distribution | awk -F ":" '{print $1}' > temp_dictionary
for line in `cat temp_dictionary`
do
if ! grep -Fxq $line $dictionary
then
echo $line >> $dictionary
fi
done
rm check
rm temp_dictionary
this is the error: (I'm translating it, so it could be different in english)
./wordOccurrences line:30 let:x // where x is a number, usually 9 or 10 (but also 11, 13, etc)
1: syntax error in the espression (the error token is 1)
sed: expression -e #1, character y: command 's' not terminated // where y is another number (this one is also usually 9 or 10) with y being different from x
EDIT:
Talking with kev it looks like it's a newline problem
I added an echo between let and sed to print the sed and it worked perfectly for like 5 to 10 minutes until that error. Usually the sed without error looked like this:
s/^CONSULENTI: 6$/CONSULENTI: 7/g
but when I got the error it was like this:
s/^00145: 1
1$/00145: 4/g
how to fix this?
If you get a new line in $old, it means awk prints two lines so there is a duplicate in $occurences.
The script seems complicated to count words, and not efficient because it launches many processes and process file in a loop ;
maybe you can do something similar with
sort | uniq -c
You should also consider that your case-insensitivity is not consistent throughout the program. I created a page with just "foooo" in it and ran the program, then created one with "Foooo" in it and ran the program again. The 'old=`awk...' line sets 'old' to the empty string because awk is matching case sensitively. This results in the occurrences file not being updated. The subsequent sed and possibly some of the greps are also case sensitive.
This may not be the only error since it doesn't explain the error message you saw, but it is an indication that the same word with different capitalization will be handled erroneously by your script.
The following would separate the words, lowercase them, and then remove the ones smaller than three characters:
tr -cs '[:alnum:]' '\n' <foo | tr '[:upper:]' '[:lower:]' | egrep -v '^.{0,2}$'
Using this at the front of your script would mean that the rest of the script would not have to be case insensitive to be correct.
So far I've been able to find out how to add a line at the beginning of a file but that's not exactly what I want. I'll show it with an example:
File content
some text at the beginning
Result
<added text> some text at the beginning
It's similar but I don't want to create any new line with it...
I would like to do this with sed if possible.
sed can operate on an address:
$ sed -i '1s/^/<added text> /' file
What is this magical 1s you see on every answer here? Line addressing!.
Want to add <added text> on the first 10 lines?
$ sed -i '1,10s/^/<added text> /' file
Or you can use Command Grouping:
$ { echo -n '<added text> '; cat file; } >file.new
$ mv file{.new,}
If you want to add a line at the beginning of a file, you need to add \n at the end of the string in the best solution above.
The best solution will add the string, but with the string, it will not add a line at the end of a file.
sed -i '1s/^/your text\n/' file
If the file is only one line, you can use:
sed 's/^/insert this /' oldfile > newfile
If it's more than one line. one of:
sed '1s/^/insert this /' oldfile > newfile
sed '1,1s/^/insert this /' oldfile > newfile
I've included the latter so that you know how to do ranges of lines. Both of these "replace" the start line marker on their affected lines with the text you want to insert. You can also (assuming your sed is modern enough) use:
sed -i 'whatever command you choose' filename
to do in-place editing.
Use subshell:
echo "$(echo -n 'hello'; cat filename)" > filename
Unfortunately, command substitution will remove newlines at the end of file. So as to keep them one can use:
echo -n "hello" | cat - filename > /tmp/filename.tmp
mv /tmp/filename.tmp filename
Neither grouping nor command substitution is needed.
To insert just a newline:
sed '1i\\'
You can use cat -
printf '%s' "some text at the beginning" | cat - filename
To add a line to the top of the file:
sed -i '1iText to add\'
my two cents:
sed -i '1i /path/of/file.sh' filename
This will work even is the string containing forward slash "/"
Hi with carriage return:
sed -i '1s/^/your text\n/' file
Note that on OS X, sed -i <pattern> file, fails. However, if you provide a backup extension, sed -i old <pattern> file, then file is modified in place while file.old is created. You can then delete file.old in your script.
There is a very easy way:
echo "your header" > headerFile.txt
cat yourFile >> headerFile.txt
PROBLEM: tag a file, at the top of the file, with the base name of the parent directory.
I.e., for
/mnt/Vancouver/Programming/file1
tag the top of file1 with Programming.
SOLUTION 1 -- non-empty files:
bn=${PWD##*/} ## bn: basename
sed -i '1s/^/'"$bn"'\n/' <file>
1s places the text at line 1 of the file.
SOLUTION 2 -- empty or non-empty files:
The sed command, above, fails on empty files. Here is a solution, based on https://superuser.com/questions/246837/how-do-i-add-text-to-the-beginning-of-a-file-in-bash/246841#246841
printf "${PWD##*/}\n" | cat - <file> > temp && mv -f temp <file>
Note that the - in the cat command is required (reads standard input: see man cat for more information). Here, I believe, it's needed to take the output of the printf statement (to STDIN), and cat that and the file to temp ... See also the explanation at the bottom of http://www.linfo.org/cat.html.
I also added -f to the mv command, to avoid being asked for confirmations when overwriting files.
To recurse over a directory:
for file in *; do printf "${PWD##*/}\n" | cat - $file > temp && mv -f temp $file; done
Note also that this will break over paths with spaces; there are solutions, elsewhere (e.g. file globbing, or find . -type f ... -type solutions) for those.
ADDENDUM: Re: my last comment, this script will allow you to recurse over directories with spaces in the paths:
#!/bin/bash
## https://stackoverflow.com/questions/4638874/how-to-loop-through-a-directory-recursively-to-delete-files-with-certain-extensi
## To allow spaces in filenames,
## at the top of the script include: IFS=$'\n'; set -f
## at the end of the script include: unset IFS; set +f
IFS=$'\n'; set -f
# ----------------------------------------------------------------------------
# SET PATHS:
IN="/mnt/Vancouver/Programming/data/claws-test/corpus test/"
# https://superuser.com/questions/716001/how-can-i-get-files-with-numeric-names-using-ls-command
# FILES=$(find $IN -type f -regex ".*/[0-9]*") ## recursive; numeric filenames only
FILES=$(find $IN -type f -regex ".*/[0-9 ]*") ## recursive; numeric filenames only (may include spaces)
# echo '$FILES:' ## single-quoted, (literally) prints: $FILES:
# echo "$FILES" ## double-quoted, prints path/, filename (one per line)
# ----------------------------------------------------------------------------
# MAIN LOOP:
for f in $FILES
do
# Tag top of file with basename of current dir:
printf "[top] Tag: ${PWD##*/}\n\n" | cat - $f > temp && mv -f temp $f
# Tag bottom of file with basename of current dir:
printf "\n[bottom] Tag: ${PWD##*/}\n" >> $f
done
unset IFS; set +f
Just for fun, here is a solution using ed which does not have the problem of not working on an empty file. You can put it into a shell script just like any other answer to this question.
ed Test <<EOF
a
.
0i
<added text>
.
1,+1 j
$ g/^$/d
wq
EOF
The above script adds the text to insert to the first line, and then joins the first and second line. To avoid ed exiting on error with an invalid join, it first creates a blank line at the end of the file and remove it later if it still exists.
Limitations: This script does not work if <added text> is exactly equal to a single period.
echo -n "text to insert " ;tac filename.txt| tac > newfilename.txt
The first tac pipes the file backwards (last line first) so the "text to insert" appears last. The 2nd tac wraps it once again so the inserted line is at the beginning and the original file is in its original order.
The simplest solution I found is:
echo -n "<text to add>" | cat - myFile.txt | tee myFile.txt
Notes:
Remove | tee myFile.txt if you don't want to change the file contents.
Remove the -n parameter if you want to append a full line.
Add &> /dev/null to the end if you don't want to see the output (the generated file).
This can be used to append a shebang to the file. Example:
# make it executable (use u+x to allow only current user)
chmod +x cropImage.ts
# append the shebang
echo '#''!'/usr/bin/env ts-node | cat - cropImage.ts | tee cropImage.ts &> /dev/null
# execute it
./cropImage.ts myImage.png
Another solution with aliases. Add to your init rc/ env file:
addtail () { find . -type f ! -path "./.git/*" -exec sh -c "echo $# >> {}" \; }
addhead () { find . -type f ! -path "./.git/*" -exec sh -c "sed -i '1s/^/$#\n/' {}" \; }
Usage:
addtail "string to add at the beginning of file"
addtail "string to add at the end of file"
With the echo approach, if you are on macOS/BSD like me, lose the -n switch that other people suggest. And I like to define a variable for the text.
So it would be like this:
Header="my complex header that may have difficult chars \"like these quotes\" and line breaks \n\n "
{ echo "$Header"; cat "old.txt"; } > "new.txt"
mv new.txt old.txt
TL;dr -
Consider using ex. Since you want the front of a given line, then the syntax is basically the same as what you might find for sed but the option of "in place editing" is built-in.
I cannot imagine an environment where you have sed but not ex/vi, unless it is a MS Windows box with some special "sed.exe", maybe.
sed & grep sort of evolved from ex / vi, so it might be better to say sed syntax is the same as ex.
You can change the line number to something besides #1 or search for a line and change that one.
source=myFile.txt
Front="This goes IN FRONT "
man true > $source
ex -s ${source} <<EOF
1s/^/$Front/
wq
EOF
$ head -n 3 $source
This goes IN FRONT TRUE(1) User Commands TRUE(1)
NAME
Long version, I recommend ex (or ed if you are one of the cool kids).
I like ex because it is portable, extremely powerful, allows me to write in-place, and/or make backups all without needing GNU (or even BSD) extensions.
Additionally, if you know the ex way, then you know how to do it in vi - and probably vim if that is your jam.
Notice that EOF is not quoted when we use "i"nsert and using echo:
str="+++ TOP +++" && ex -s <<EOF
r!man true
1i
`echo "$str"`
.
"0r!echo "${str}"
wq! true.txt
EOF
0r!echo "${str}" might also be used as shorthand for :0read! or :0r! that you have likely used in vi mode (it is literally the same thing) but the : is optional here and some implementations do not support "r"ead address of zero.
"r"eading directly to the special line #0 (or from line 1) would automatically push everything "down", and then you just :wq to save your changes.
$ head -n 3 true.txt | nl -ba
1 +++ TOP +++
2 TRUE(1) User Commands TRUE(1)
3
Also, most classic sed implementations do not have extensions (like \U&) that ex should have by default.
cat concatenates multiple files. <() sends output of a command as a file. Combining these two, we can insert lines at the beginning and end of a file by,
cat <(echo "line before the file") file.txt <(echo "line after the file")