I am trying using grep command to obtain the line number of a specific string from a txt file using linux.
For example, I have a text file that contains
asdf
ghjk
zxcv
If I grep this file for asdf, we will receive the integer with number 1.
If I grep this file for zxcv, we will receive the integer with number 3.
How can return the line number with grep?
To return the line number from grep, use the -n switch. You can pipe the output of grep to the cut command to parse out the :<search_string> as well.
grep -n <pattern> <file> | cut -f1 -d:
If your file(test.txt) has the below contents ...
asdf
ghjk
zxcv
asdf
You would get the following output for a single occurance ...
$ grep -n ghjk test.txt | cut -f1 -d:
2
You would get multiple line numbers returned in the case where your search criteria is in multiple lines within the file.
$ grep -n asdf test.txt | cut -f1 -d:
1
4
Related
I have a file with content as follows and want to validate the content as
1.I have entries of rec$NUM and this field should be repeated 7 times only.
for example I have rec1.any_attribute this rec1 should come only 7 times in whole file.
2.I need validating script for this.
If records for rec$NUM are less than 7 or Greater than 7 script should report that record.
FILE IS AS FOLLOWS :::
rec1:sourcefile.name=
rec1:mapfile.name=
rec1:outputfile.name=
rec1:logfile.name=
rec1:sourcefile.nodename_col=
rec1:sourcefle.snmpnode_col=
rec1:mapfile.enc=
rec2:sourcefile.name=abc
rec2:mapfile.name=
rec2:outputfile.name=
rec2:logfile.name=
rec2:sourcefile.nodename_col=
rec2:sourcefle.snmpnode_col=
rec2:mapfile.enc=
rec3:sourcefile.name=abc
rec3:mapfile.name=
rec3:outputfile.name=
rec3:logfile.name=
rec3:sourcefile.nodename_col=
rec3:sourcefle.snmpnode_col=
rec3:mapfile.enc=
Please Help
Thanks in Advance... :)
Simple awk:
awk -F: '/^rec/{a[$1]++}END{for(t in a){if(a[t]!=7){print "Some error for record: " t}}}' test.rc
grep '^rec1' file.txt | wc -l
grep '^rec2' file.txt | wc -l
grep '^rec3' file.txt | wc -l
All above should return 7.
The commands:
grep rec file2.txt | cut -d':' -f1 | uniq -c | egrep -v '^ *7'
will success if file follows your rules, fails (and returns the failing record) if it doesn't.
(replace "uniq -c" by "sort -u" if record numbers can be mixed).
I need to get a list of matches with grep including filename and line number but without the match string
I know that grep -Hl will give only file names and grep -Hno will give filename with only matching string. But those not ideal for me. I need to get a list without match but with line no. For this grep -Hln doesn't work. I tried with grep -Hn 'pattern' | cut -d " " -f 1 But it doesn't cut the filename and line no properly.
awk can do that in single command:
awk '/pattern/ {print FILENAME ":" NR}' *.txt
You were pointing it well with cut, only that you need the : field separator. Also, I think you need the first and second group. Hence, use:
grep -Hn 'pattern' files* | cut -d: -f1,2
Sample
$ grep -Hn a a*
a:3:are
a:10:bar
a:11:that
a23:1:hiya
$ grep -Hn a a* | cut -d: -f1,2
a:3
a:10
a:11
a23:1
I guess you want this, just line numbers:
grep -nh PATTERN /path/to/file | cut -d: -f1
example output:
12
23
234
...
Unfortunately you'll need to use cut here. There is no way to do it with pure grep.
Try
grep -RHn Studio 'pattern' | awk -F: '{print $1 , ":", $2}'
How can I apply the following command to only a part of a text file? For example from the beginning to the line 5000.
grep "^ A : 11 B : 10" filename | wc -l
I cannot use head and then apply the above command since the text file is huge.
You could try using the sed command, which I believe does better for large files, from this question and pipe to grep.
sed -n 1,5000p file | grep ...
You can try combination of -n (prefixing each line of output with line number) and -m (limiting number of matching lines). Something like this:
grep -n -m 5000 pattern file.txt | grep -B 5000 "^5000:" | wc -l
First grep search for pattern, add line numbers and limit output to first 5000 matching lines (worst case scenario: all lines from range match pattern). Second grep match line number 5000, and print all lines before this line.
I don't know if it is more efficient solution
In a very large file I need to find the position (line number) of a string, then extract the 2 lines above and below that string.
To do this right now - I launch vi, find the string, note it's line number, exit vi, then use sed to extract the lines surrounding that string.
Is there a way to streamline this process... ideally without having to run vi at all.
Maybe using grep like this:
grep -n -2 your_searched_for_string your_large_text_file
Will give you almost what you expect
-n : tells grep to print the line number
-2 : print 2 additional lines (and the wanted string, of course)
You can do
grep -C 2 yourSearch yourFile
To send it in a file, do
grep -C 2 yourSearch yourFile > result.txt
Use grep -n string file to find the line number without opening the file.
you can use cat -n to display the line numbers and then use awk to get the line number after a grep in order to extract line number:
cat -n FILE | grep WORD | awk '{print $1;}'
although grep already does what you mention if you give -C 2 (above/below 2 lines):
grep -C 2 WORD FILE
You can do it with grep -A and -B options, like this:
grep -B 2 -A 2 "searchstring" | sed 3d
grep will find the line and show two lines of context before and after, later remove the third one with sed.
If you want to automate this, simple you can do a Shell Script. You may try the following:
#!/bin/bash
VAL="your_search_keyword"
NUM1=`grep -n "$VAL" file.txt | cut -f1 -d ':'`
echo $NUM1 #show the line number of the matched keyword
MYNUMUP=$["NUM1"-1] #get above keyword
MYNUMDOWN=$["NUM1"+1] #get below keyword
sed -n "$MYNUMUP"p file.txt #display above keyword
sed -n "$MYNUMDOWN"p file.txt #display below keyword
The plus point of the script is you can change the keyword in VAL variable as you like and execute to get the needed output.
I have a text file and I need to search that file and figure how many blank lines are in the file. A blank line is a line with no characters.
I must use egrep.
[aman#localhost ~]$ cat >try
sldjjsd
dkfjkjdf
dfkjdf
[aman#localhost ~]$ egrep '^$' try|wc -l
4
This will do.
egrep '^$' blankfile -c
Another way, without egrep.
echo $(($(cat blank | wc -l)-$(cat blank | tr -s "\n" | wc -l)))