Manipulation of text by programs, scripts, etc.

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2answers
4k views

How do I insert a space every four characters in a long line?

I've got a long line that I want to insert a space every 4 characters, on a single lone line of solid text to make it easier to read, what's the simplest way to do this? also I should be able to input ...
6
votes
3answers
182 views

Shell script to search files for identical text entries

Here's a nice teaser for a shell scripting guru: Take a directory with several text files. Can be a few up to ~1000. All files contain an identifier on a given line (always the same line). Identify ...
6
votes
6answers
219 views

Obtain values of a section of a file

I have a configuration file in the following format. <Title> [part1] A.File = a A.Val = val1 B.File = a B.Val = val1 [part2] A.File = a1 A.Val = val2 B.File = a B.Val = val1 ...
6
votes
7answers
239 views

Count total number of lines before/after a pattern match

I am having a long list of IP addresses, which are not in sequence. I need to find how many IP addresses are there before/after a particular IP address. How can I achieve this?
6
votes
4answers
641 views

We need a “C” list that contains all the elements of “A”, but doesn't have any of “B”

We have two lists. A bigger "A": A=`echo -e '1\n2\n3\n4\n5'` echo "$A" 1 2 3 4 5 and a smaller "B": B=`echo -e '1\n2\n3'` echo "$B" 1 2 3 Q: But we need a third list that contains all the ...
6
votes
3answers
472 views

Remove only the commas present within the double quotes

In a text file, I want to remove , (commas) and also the " (quotes) (only if the double quotes contains numbers seperated by commas). 56,72,"12,34,54",x,y,"foo,a,b,bar" Expected ouput ...
6
votes
4answers
273 views

How can I print a conditional header BEFORE stdout, if there is any output on stdout

I have a process that filters a list of files from a directory (having find check to see if there are files older than a certain period to show a queue is stuck). It may or may not return anything, ...
6
votes
3answers
25k views

How to use regex with AWK for string replacement?

Suppose there is some text from a file: (bookmarks ("Chapter 1 Introduction 1" "#1" ("1.1 Problem Statement and Basic Definitions 23" "#2") ("Exercises 31" "#30") ("Notes and References 42" "#34")) ) ...
6
votes
4answers
312 views

Getting text from last marker to EOF in POSIX.2

I have a text with marker lines like: aaa --- bbb --- ccc I need to get a text from the last marker (not inclusive) to EOF. In this case it will be ccc Is there an elegant way within POSIX.2? ...
6
votes
2answers
521 views

Find all files with a Python Shebang

I'm trying to run a PEP8 check against a large source tree. The tree is comprised of a mix of files in various languages. The idea is to check all the Python scripts without having to explicitly list ...
6
votes
3answers
6k views

How to insert a line into text document right before line containing some text in bash?

I have a variable say $strToInsert I have a file file.html I wonder how to find last appearence of </head> and insert a new line before line with it and fill it with $strToInsert contents? ...
6
votes
1answer
516 views

How to detect and delete lines containing ˆ@

I have a simple problem: In my file, the are lines containing the string ˆ@ˆ@ˆ@ˆ@ˆ@ˆ@. I just want to delete all lines with this string, using for example the sed or grep commands. And I would like ...
6
votes
5answers
3k views

Compare two files with first column and remove duplicate row from 2nd file in shell script

I will ask my question with an example. I have 2 files: File #1: 118D FC300_R5_TP FX.B 32775 2112 6 2038 6 2112 0 118E FC300_R5_TP FX.B 32775 2136 7 ...
6
votes
3answers
537 views

How to replace all percent-encoded UTF-8 substrings with plain UTF-8 text?

I've got a html file with a lot of %-encoded UTF-8 text in URLs. For example "%D1%80%D0%B5%D1%81%D1%83%D1%80%D1%81%D1%8B" stands for "ресурсы" ("resources" in Russian). The task is to replace all ...
6
votes
4answers
1k views

Any (text based) plotting tools in unix toolbox?

I was wondering if there are any generic plotting tools available in the unix toolbox? By plotting I mean simple bars or things you see in many curses based utilities. And by unix toolbox I mean ...
6
votes
2answers
197 views

How to report “sed” in-place changes

When using sed to replace strings in-place, is there a way to make it report the changes it does (without relying on a diff of old and new files)? For instance, how can I change the command line ...
6
votes
2answers
354 views

bash: colorize second column of output

let's say, I have following output from ls: $ ls -lAhF /bin -rwxr-xr-x 1 root root 905K Apr 10 2010 bash* -rwxr-xr-x 3 root root 31K Dec 26 2011 bunzip2* -rwxr-xr-x 1 root root 505K Nov 15 2010 ...
6
votes
4answers
206 views

remove lines that is newer than the given date in a file

I'm stuck on how I can go about deleting lines that are newer than given date. Here is a snippet of contents of a file. buildsave.txt 647919 2013/11/30 647946 2013/11/30 647955 2013/12/01 648266 ...
6
votes
1answer
135 views

counting the number of occurences in a file of data list

I have a data file, like 7 2 10 9 10 3 2 4 2 4 6 Each line has a single value. I want to count the occurence of each value. For instance, 10 occurs two times in this file. Is there a simple way ...
6
votes
5answers
167 views

Remove backslash + newline sequences

We are having a file in Linux which contains one line per record, but problem comes when the line contains some new line characters. In this case, the backslash is appended at the end of line and the ...
6
votes
2answers
216 views

Number of comma-separated fields in a text file

I'm trying to build an awk statement to read this file: A 1,2,3 * A 4,5,6 ** B 1 B 4,5 * and build a file like this: A 1,2,3 * 3 1 0.333 A 4,5,6 ** 3 2 0.666 B ...
6
votes
4answers
151 views

How to insert lines with numbers from X to Y into another file after line Z?

I created two files: echo -e "1\n2\n3\n4\n5" > 123.txt echo -e "a\nb\nc\nd\ne" > abc.txt I want to get the file 123.txt with the following contents: 1 2 3 b c d 4 5 So in other words ...
6
votes
1answer
2k views

How can I replace a string in a file(s)?

Replacing strings in files based on certain search criteria is a very common task. How can I replace string foo with bar in all files in the current directory? do the same recursively for sub ...
6
votes
2answers
150 views

What is the connection between a gedit bug and a Unix-&-Linux Q/A href?

While answering a Unix-&-Linux question, I observed that Gedit and two other editors, Leafpad and Medit (I tested 12 editors altogether) exhibit the a certain bug. As it turns out, the bug is ...
6
votes
6answers
328 views

Split large file into chunks without splitting entry

I have a rather large .msg file formatted in the UIEE format. $ wc -l big_db.msg 8726593 big_db.msg Essentially, the file is made up of entries of various length that look something like this: ...
6
votes
2answers
914 views

How can I use column to delimit on tabs and not spaces?

I'd like to use Unix column to format some text. I have fields delimited by tabs, but within each field there are also spaces. column delimits on white space (tabs and spaces). How can I make column ...
6
votes
1answer
119 views

Is there a command like head but for line truncation?

Linux's head selects a number of lines from the top of a file. Is there a command that selects a number of characters from the front of a line? The use case behind the question is this: I want to ...
6
votes
3answers
74 views

Print a multiline variable in a column

I have a script that collects values from a cluster. The values, in some cases, have multiple lines. I have a printf format that specifies how the data should be positioned however, it doesn't take ...
6
votes
6answers
90 views

How can I avoid escaped delimiter characters in a Unix command?

I need to take the sum of a field which is tilde (~) delimited. Problem I have is that my data is also having delimiter escaped. Example 1~CEO~ashok\~kumar~1000 As we see in 3rd field above we ...
6
votes
4answers
366 views

extracting certain info from output

I'm trying to extract certain info from ffmpeg output. Sample ffmpeg output: configuration: --enable-memalign-hack --enable-mp3lame --enable-gpl --disable-vhook --disable-ffplay --disable-ffserver ...
6
votes
4answers
392 views

Fastest way to determine if two sorted lists contain unique elements

I have two sorted files A and B where the size of A is much greater than B, e.g. A is 100GB while B is 50MB. I want to quickly determine if there are any lines in B that are contained in A, stopping ...
6
votes
2answers
657 views

shell script/utility replace 2 byte unicode in binary file

I have many large Unicode files. I would like to replace each Unicode byte pair with a new Unicode byte pair. For example, the original file contains "C3 B9 C3 AB C3 B8 C3 B0" and I would like to ...
5
votes
6answers
543 views

What is the easiest way to add a string on the beginning of every line of the file from the command line?

I am looking for a way to add some string to the beginning of every line (same string for every line). Not something customizable but rather something that will be easy to remember and available on ...
5
votes
3answers
335 views

Counting the occurrences of the string

As input, we have some ids which are strings. How do we calculate what identifier has appeared most frequently and how many times? Example Input: cat dog cat dog dog dog dog fly spider spider ...
5
votes
4answers
425 views

How can I “lazily” read output from xrandr?

I have a bash script that I use to adjust my monitor brightness that uses xrandr --verbose to get the current brightness. It works fine, but using xrandr is kind of slow on my machine, as you can see ...
5
votes
5answers
277 views

Sorting blocks of lines

I have a file that contains 4n lines. Here is an excerpt from it containing 8 lines 6115 8.88443 6116 6.61875 6118 16.5949 6117 19.4129 6116 6.619 6117 16.5979 6118 19.4111 6115 8.88433 What I ...
5
votes
4answers
638 views

Look for English word in a file via terminal

How to find and print out English words contained in a file via linux command line?
5
votes
4answers
322 views

reverse order of paragraphs in file

I have a file containing text in paragraphs (lines with text separated by one or more empty lines). I would like to reverse the order of paragraphs (i.e. last paragraph will become the first, ...), ...
5
votes
5answers
2k views

How to append data of multiple files into single file?

For example: I have 01.txt and 02.txt files and need to append data of these files into new file new.txt. It should append data based on 01.txt followed by 02.txt files. Before this I have to delete ...
5
votes
1answer
442 views

inexact text search

Is there any utility like grep or even uniq but for inexact search or I should write it myself? I mean it will look at 90% (number may vary) matching, or smth like that. For example I have file with ...
5
votes
5answers
17k views

Multiline pattern match using sed, awk or grep

Is it possible to do a multiline pattern match using sed, awk or grep? Take for example, I would like to get all the lines between { and } So it should be able to match 1. {} 2. {.....} 3. ...
5
votes
3answers
1k views

Fast way to build a test file with every second listed in YYYY-mm-dd HH:MM:SS format

I want to create a large test file with lines containg dates listed by the second, but my method is taking inordinately long... (or at least, that's how it feels :) ... 43 minutes to create only ...
5
votes
2answers
1k views

sort output by column

I'd like to take this command find -maxdepth 1 -type d | while read -r dir; do printf "%s:\t" "$dir"; find "$dir" | wc -l; done ( from here ). which has an output of basically ./kennel: 11062 ...
5
votes
4answers
224 views

How could I simplify this command to only use awk?

awk '/user/ {print $1 }' /etc/userdomains | sed 's/://' the format of /etc/userdomains is domain.tld: user otherdomain.tld: otheruser
5
votes
3answers
251 views

How to have command history with timestamps output to the terminal continuously?

I use a simple alias to enable the "tracking" of commands in one or many terminal window(s): alias trackmi='export PROMPT_COMMAND="history -a; $PROMPT_COMMAND"' Then I just tail -f my .bash_history ...
5
votes
4answers
1k views

how do I trim each line in bash?

I would like to remove all leading and trailing spaces and tabs from each line in an output. Is there a simple tool like trim I could pipe my output into?
5
votes
4answers
4k views

Is it possible in bash, to start reading a file from an arbitary byte count offset?

I want to locate a date which is somewhere in an 8 GB log (text). Can I somewhat bypass a full sequential read, and first do binary splits of the file (size), or somehow navigating the filesystem ...
5
votes
3answers
264 views

removing redundancy from output columns

What is a *NIX way of removing redundancy in a case where I have pairwise comparisons like these in two columns A B B A A C A D C A D A B C C B A B and B A ...
5
votes
3answers
3k views

How can sed output be formatted like printf's formatted printing?

Can sed replace text with a string formatted like printf's formatted printing? The following sed command replaces a line starting with the current value of "$domain" with several values specified in ...
5
votes
3answers
2k views

Collapsing a stream of multiple lines into one line

I have a file containing a a large number of lines, each of which contains a bunch of numbers which are separated by spaces. I process this data in a pipe in some way, and then I want to collapse the ...