i am using this code
cut -c1 | tr -d '\n'
to basically take and print out the first letter of every line. the problem is, I need a new line at the end, but only at the end, after the word "caroline" (these are the content of the testfile
Cannot use AWK, basename, grep, egrep, fgrep or rgrep
Use echo
echo $( cut -c1 | tr -d '\n' ) \n
cut -c1 | tr -d '\n'; echo -e '\n'
Try using awk utility, something like following:-
awk -F\| '$1 > 0 { print substr($1,1,1)}' testfile.txt
I'm trying to use a list of patterns to search in 4 large files, and remove the line that contains the regex.
I tried to specify the file path but it didn't work
sed -n '/{home/dirco/shut}/p' rimco rimco2 aval aval2
I tried to use sed option -f but it didn't work either
sed -f home/dirco/shut rimco rimco2 aval aval2
ultimately the goal will be to sed in place by removing that line if the pattern is found.
This might work for you (GNU sed):
sed 's#/#\\/#g;s#.*#/&/p#g' patternFile | sed -nf - file1 file2 file3 ...
Turn the patternFile into a sed script and run it against the data files.
N.B. The sed delimiter / is first quoted and the each line of the patternFile is turned into an address which is printed /pattern/p.
try this:
cmd=$(
echo -n "sed -i '"
while read -r line; do
echo -n "/$line/d;"
done < patternfile.txt
echo "'"
)
"$cmd" rimco rimco2 aval aval2
Here's how to do what you want efficiently and robustly by using GNU awk for inplace editing (assuming your list of regexps in regexpsfile isn't massive):
awk -i inplace 'NR==FNR{re=re sep "(" $0 ")"; sep="|"} NR!=FNR && $0~re{next} 1' regexpsfile rimco rimco2 aval aval2
For example
echo "abc-1234a :" | grep <do-something>
to print only abc-1234a
I think these are closer to what you're getting at, but without knowing what you're really trying to achieve, it's hard to say.
echo "abc-1234a :" | egrep -o '^[^:]+'
... though this will also match lines that have no colon. If you only want lines with colons, and you must use only grep, this might work:
echo "abc-1234a :" | grep : | egrep -o '^[^:]+'
Of course, this only makes sense if your echo "abc-1234a :" is an example that would be replace with possibly multiple lines of input.
The smallest tool you could use is probably cut:
echo "abc-1234a :" | cut -d: -f1
And sed is always available...
echo "abc-1234a :" | sed 's/ *:.*//'
For this last one, if you only want to print lines that include a colon, change it to:
echo "abc-1234a :" | sed -ne 's/ *:.*//p'
Heck, you could even do this in pure bash:
while read line; do
field="${line%%:*}"
# do stuff with $field
done <<<"abc-1234a :"
For information on the %% bit, you can man bash and search for "Parameter Expansion".
UPDATE:
You said:
It's the characters in the first line of input before the colon. The
input could have multiple line though.
The solutions with grep probably aren't your best choice, then, since they'll also print data from subsequent lines that might include colons. Of course, there are many ways to solve this requirement as well. We'll start with sample input:
$ function sample { printf "abc-1234a:foo\nbar baz:\nNarf\n"; }
$ sample
abc-1234a:foo
bar baz:
Narf
You could use multiple pipes, for example:
$ sample | head -1 | grep -Eo '^[^:]*'
abc-1234a
$ sample | head -1 | cut -d: -f1
abc-1234a
Or you could use sed to process only the first line:
$ sample | sed -ne '1s/:.*//p'
abc-1234a
Or tell sed to exit after printing the first line (which is faster than reading the whole file):
$ sample | sed 's/:.*//;q'
abc-1234a
Or do the same thing but only show output if a colon was found (for safety):
$ sample | sed -ne 's/:.*//p;q'
abc-1234a
Or have awk do the same thing (as the last 3 examples, respectively):
$ sample | awk '{sub(/:.*/,"")} NR==1'
abc-1234a
$ sample | awk 'NR>1{nextfile} {sub(/:.*/,"")} 1'
abc-1234a
$ sample | awk 'NR>1{nextfile} sub(/:.*/,"")'
abc-1234a
Or in bash, with no pipes at all:
$ read line < <(sample)
$ printf '%s\n' "${line%%:*}"
abc-1234a
It is possible to do what you want with only sed.
Here is an example:
#!/bin/sh
filename=$1
pattern=yourpattern
# flag -n disables print everyline (default behavior)
sed -n "
1,/$pattern/ {
/$pattern/n # skip line containing pattern
p # print lines ranging from line 1 untill pattern
}
" $filename
exit 0
This works at least for GNU's sed. It should work for other sed too, except
regarding the comments (some implementations of sed don't support comments).
Source: https://www.grymoire.com/Unix/Sed.html
I am using grep recursive to search files for a string, and all the matched files and the lines containing that string are print on the terminal. But is it possible to get the line numbers of those lines too??
ex: presently what I get is /var/www/file.php: $options = "this.target", but what I am trying to get is /var/www/file.php: 1142 $options = "this.target";, well where 1142 would be the line number containing that string.
Syntax I am using to grep recursively is sudo grep -r 'pattern' '/var/www/file.php'
One more question is, how do we get results for not equal to a pattern. Like all the files but not the ones having a certain string?
grep -n SEARCHTERM file1 file2 ...
Line numbers are printed with grep -n:
grep -n pattern file.txt
To get only the line number (without the matching line), one may use cut:
grep -n pattern file.txt | cut -d : -f 1
Lines not containing a pattern are printed with grep -v:
grep -v pattern file.txt
If you want only the line number do this:
grep -n Pattern file.ext | gawk '{print $1}' FS=":"
Example:
$ grep -n 9780545460262 EXT20130410.txt | gawk '{print $1}' FS=":"
48793
52285
54023
grep -A20 -B20 pattern file.txt
Search pattern and show 20 lines after and before pattern
grep -nr "search string" directory
This gives you the line with the line number.
In order to display the results with the line numbers, you might try this
grep -nr "word to search for" /path/to/file/file
The result should be something like this:
linenumber: other data "word to search for" other data
When working with vim you can place
function grepn() {
grep -n $# /dev/null | awk -F $':' '{t = $1; $1 = $2; $2 = t; print; }' OFS=$':' | sed 's/^/vim +/' | sed '/:/s// /' | sed '/:/s// : /'
}
in your .bashrc and then
grepn SEARCHTERM file1 file2 ...
results in
vim +123 file1 : xxxxxxSEARCHTERMxxxxxxxxxx
vim +234 file2 : xxxxxxSEARCHTERMxxxxxxxxxx
Now, you can open vim on the correspondending line (for example line 123) by simply copying
vim +123 file1
to your shell.
How do I join the result of ls -1 into a single line and delimit it with whatever I want?
paste -s -d joins lines with a delimiter (e.g. ","), and does not leave a trailing delimiter:
ls -1 | paste -sd "," -
EDIT: Simply "ls -m" If you want your delimiter to be a comma
Ah, the power and simplicity !
ls -1 | tr '\n' ','
Change the comma "," to whatever you want. Note that this includes a "trailing comma" (for lists that end with a newline)
This replaces the last comma with a newline:
ls -1 | tr '\n' ',' | sed 's/,$/\n/'
ls -m includes newlines at the screen-width character (80th for example).
Mostly Bash (only ls is external):
saveIFS=$IFS; IFS=$'\n'
files=($(ls -1))
IFS=,
list=${files[*]}
IFS=$saveIFS
Using readarray (aka mapfile) in Bash 4:
readarray -t files < <(ls -1)
saveIFS=$IFS
IFS=,
list=${files[*]}
IFS=$saveIFS
Thanks to gniourf_gniourf for the suggestions.
I think this one is awesome
ls -1 | awk 'ORS=","'
ORS is the "output record separator" so now your lines will be joined with a comma.
Parsing ls in general is not advised, so alternative better way is to use find, for example:
find . -type f -print0 | tr '\0' ','
Or by using find and paste:
find . -type f | paste -d, -s
For general joining multiple lines (not related to file system), check: Concise and portable “join” on the Unix command-line.
The combination of setting IFS and use of "$*" can do what you want. I'm using a subshell so I don't interfere with this shell's $IFS
(set -- *; IFS=,; echo "$*")
To capture the output,
output=$(set -- *; IFS=,; echo "$*")
Adding on top of majkinetor's answer, here is the way of removing trailing delimiter(since I cannot just comment under his answer yet):
ls -1 | awk 'ORS=","' | head -c -1
Just remove as many trailing bytes as your delimiter counts for.
I like this approach because I can use multi character delimiters + other benefits of awk:
ls -1 | awk 'ORS=", "' | head -c -2
EDIT
As Peter has noticed, negative byte count is not supported in native MacOS version of head. This however can be easily fixed.
First, install coreutils. "The GNU Core Utilities are the basic file, shell and text manipulation utilities of the GNU operating system."
brew install coreutils
Commands also provided by MacOS are installed with the prefix "g". For example gls.
Once you have done this you can use ghead which has negative byte count, or better, make alias:
alias head="ghead"
Don't reinvent the wheel.
ls -m
It does exactly that.
just bash
mystring=$(printf "%s|" *)
echo ${mystring%|}
This command is for the PERL fans :
ls -1 | perl -l40pe0
Here 40 is the octal ascii code for space.
-p will process line by line and print
-l will take care of replacing the trailing \n with the ascii character we provide.
-e is to inform PERL we are doing command line execution.
0 means that there is actually no command to execute.
perl -e0 is same as perl -e ' '
To avoid potential newline confusion for tr we could add the -b flag to ls:
ls -1b | tr '\n' ';'
It looks like the answers already exist.
If you want
a, b, c format, use ls -m ( Tulains Córdova’s answer)
Or if you want a b c format, use ls | xargs (simpified version of Chris J’s answer)
Or if you want any other delimiter like |, use ls | paste -sd'|' (application of Artem’s answer)
The sed way,
sed -e ':a; N; $!ba; s/\n/,/g'
# :a # label called 'a'
# N # append next line into Pattern Space (see info sed)
# $!ba # if it's the last line ($) do not (!) jump to (b) label :a (a) - break loop
# s/\n/,/g # any substitution you want
Note:
This is linear in complexity, substituting only once after all lines are appended into sed's Pattern Space.
#AnandRajaseka's answer, and some other similar answers, such as here, are O(n²), because sed has to do substitute every time a new line is appended into the Pattern Space.
To compare,
seq 1 100000 | sed ':a; N; $!ba; s/\n/,/g' | head -c 80
# linear, in less than 0.1s
seq 1 100000 | sed ':a; /$/N; s/\n/,/; ta' | head -c 80
# quadratic, hung
sed -e :a -e '/$/N; s/\n/\\n/; ta' [filename]
Explanation:
-e - denotes a command to be executed
:a - is a label
/$/N - defines the scope of the match for the current and the (N)ext line
s/\n/\\n/; - replaces all EOL with \n
ta; - goto label a if the match is successful
Taken from my blog.
If you version of xargs supports the -d flag then this should work
ls | xargs -d, -L 1 echo
-d is the delimiter flag
If you do not have -d, then you can try the following
ls | xargs -I {} echo {}, | xargs echo
The first xargs allows you to specify your delimiter which is a comma in this example.
ls produces one column output when connected to a pipe, so the -1 is redundant.
Here's another perl answer using the builtin join function which doesn't leave a trailing delimiter:
ls | perl -F'\n' -0777 -anE 'say join ",", #F'
The obscure -0777 makes perl read all the input before running the program.
sed alternative that doesn't leave a trailing delimiter
ls | sed '$!s/$/,/' | tr -d '\n'
Python answer above is interesting, but the own language can even make the output nice:
ls -1 | python -c "import sys; print(sys.stdin.read().splitlines())"
You can use:
ls -1 | perl -pe 's/\n$/some_delimiter/'
If Python3 is your cup of tea, you can do this (but please explain why you would?):
ls -1 | python -c "import sys; print(','.join(sys.stdin.read().splitlines()))"
ls has the option -m to delimit the output with ", " a comma and a space.
ls -m | tr -d ' ' | tr ',' ';'
piping this result to tr to remove either the space or the comma will allow you to pipe the result again to tr to replace the delimiter.
in my example i replace the delimiter , with the delimiter ;
replace ; with whatever one character delimiter you prefer since tr only accounts for the first character in the strings you pass in as arguments.
You can use chomp to merge multiple line in single line:
perl -e 'while (<>) { if (/\$/ ) { chomp; } print ;}' bad0 >test
put line break condition in if statement.It can be special character or any delimiter.
Quick Perl version with trailing slash handling:
ls -1 | perl -E 'say join ", ", map {chomp; $_} <>'
To explain:
perl -E: execute Perl with features supports (say, ...)
say: print with a carrier return
join ", ", ARRAY_HERE: join an array with ", "
map {chomp; $_} ROWS: remove from each line the carrier return and return the result
<>: stdin, each line is a ROW, coupling with a map it will create an array of each ROW