Questions tagged [tr]
For questions pertaining to tr, a utility that translates or deletes characters. Use this tag for questions about the tr utility itself, or questions about issues arising from its use.
189
questions
121
votes
7
answers
213k
views
Convert file contents to lower case
I have temp file with some lower-case and upper-case contents.
Input
Contents of my temp file:
hi
Jigar
GANDHI
jiga
I want to convert all upper to lower.
Command
I tried the following command:
...
- 4,830
118
votes
6
answers
280k
views
Replace multiple spaces with one using 'tr' only
I have a file, f1.txt:
ID Name
1 a
2 b
3 g
6 f
The number of spaces is not fixed. What is the best way to replace all the white spaces with one space using only tr?
...
- 3,229
57
votes
6
answers
37k
views
Why can't tr read from /dev/urandom on OSX?
A colleague suggested creating a random key via the following command:
tr -dc A-Za-z0-9_\!\@\#\$\%\^\&\*\(\)-+= < /dev/urandom | head -c 32 | xargs
It gave me the error:
tr: Illegal byte ...
- 1,117
55
votes
6
answers
68k
views
Replace all newlines to space except the last
How can I replace all newlines with space except the last newline.
I can replace all newline to space using tr but how I can do it with some exceptions?
user59930
51
votes
3
answers
132k
views
Removing all spaces, tabs, newlines, etc from a variable?
This is the error I am getting and it's failing because of a variable whose value is supposed to be 2 (I am getting this using a select * from tabel).
I am getting spaces in that variable.
+ 0 !=
...
- 7,825
42
votes
2
answers
60k
views
tr complains of “Illegal byte sequence”
I'm brand new to UNIX and I am using Kirk McElhearn's "The Mac OS X Command Line" to teach myself some commands.
I am attempting to use tr and grep so that I can search for text strings in a regular ...
- 421
42
votes
2
answers
15k
views
How to make tr aware of non-ascii(unicode) characters?
I'm trying to remove some characters from file(UTF-8). I'm using tr for this purpose:
tr -cs '[[:alpha:][:space:]]' ' ' <testdata.dat
File contains some foreign characters (like "Латвийская" or "...
- 6,836
24
votes
8
answers
46k
views
Turning separate lines into a comma separated list with quoted entries
I have the following data (a list of R packages parsed from a Rmarkdown file), that I want to turn into a list I can pass to R to install:
d3heatmap
data.table
ggplot2
htmltools
htmlwidgets
...
- 373
22
votes
6
answers
5k
views
Generating a random password; why isn't this portable?
I want to generate a random password, and am doing it like so:
</dev/urandom tr -dc [:print:] | head -c 64
On my laptop, which runs Ubuntu, this produces only printable characters, as intended. ...
- 491
20
votes
5
answers
133k
views
How do I remove spaces from shell variables?
I have done the following at command line:
$ text="name with space"
$ echo $text
name with space
I am trying to use tr -d ' ' to remove the spaces and have a result of:
namewithspace
I've tried a ...
- 465
18
votes
3
answers
4k
views
What do the dots in this tr command do: tr .............A-Z A-ZA-Z <<< "JVPQBOV" (with 13 dots)
I want to use tr to do some rot13 transformation. I can beautifully understand this command:
tr A-Za-z N-ZA-Mn-za-m <<< "URYC ZR CYRNFR"
which output is HELP ME PLEASE, but I can't figure ...
17
votes
3
answers
7k
views
Can I use `sed` to translate characters like with `tr`?
I would like to replace a set of characters with corresponding characters from another set, something like this:
original set: ots
"target" set: u.x
foobartest → fuubar.ex.
Translations/...
- 7,918
16
votes
2
answers
65k
views
Fastest & Most Core way to replace "\r\n" with "\n" in a file?
I suppose tr is a more core method and thus probably a faster way to replace things within a given file.
However tr can only replace equal amounts of characters. meaning...
2 characters can only be ...
- 163
13
votes
2
answers
40k
views
How does tr '[a-z]' '[n-za-m]' work?
I found an obfuscated e-mail address that can be decrypted using this command:
echo "[email protected]" | tr '[a-z]' '[n-za-m]'
How does that output a valid e-mail address? What is that command ...
- 39.5k
13
votes
3
answers
16k
views
Main difference between tr (translate) to sed and awk
AFAIC both sed and awk are general purpose text processing utilities with whom a user can get quite similar results, in a slightly different syntax:
With both, a user could add, replace/translate and ...
13
votes
1
answer
5k
views
Why does the tr command not read from file?
I looked up a Unix book, the man and the wikipedia page for tr but could not find a reason why it was designed/implemented in such way that it does not read from file but strictly only from the ...
- 9,086
12
votes
2
answers
4k
views
Can I disable buffering for tr
tr seems to buffer its input so that this command LongRunningCommand|tr \\n , will only start producing output after a few kilobytes of input from LongRunningCommand have accumulated.
Is there a way ...
- 2,679
11
votes
2
answers
2k
views
Strange behaviour of tr using ranges
I have one particular server that is exhibiting strange behaviour when using tr. Here is an example from a working server:
-bash-3.2$ echo "abcdefghijklmnopqrstuvwxyz1234567890"|tr -d [a-z]
...
- 121
11
votes
4
answers
38k
views
Can tr work with regex?
I have a file like this:
AAAA
BBBB
CCCC
DDDD
etc
Words in separate lines. I want to add them quotes using tr.
So I tried the following:
1) To add a quote in the start of each word i....
- 9,780
11
votes
3
answers
18k
views
Can tr commands be chained to avoid multiple tr processes in a pipeline?
I have a bunch of txt files, I'd like to output them lower-cased, only alphabetic and one word-per line, I can do it with several tr commands in a pipeline like this:
tr -d '[:punct:]' <...
- 571
11
votes
2
answers
2k
views
What's the difference between `-C` and `-c` in `tr` command?
Today I learnt a bit about tr command.
But I was stuck at understanding the difference between -c and -C.
On the manual, it said:
-C Complement the set of characters in string1, that is ``-C ...
- 7,297
10
votes
3
answers
6k
views
How to convert UTF-8 txt files to all uppercase in bash?
I have some UTF-8 .txt files which I would like to convert to all uppercase. If it was just ASCII, I could use:
tr [:lower:] [:upper:]
But since I'm working with diacritics and stuff, it doesn't ...
- 627
10
votes
1
answer
2k
views
tr a A < /etc/hosts | sort -r |pr -d > /etc/hosts
In this line:
tr a A < /etc/hosts | sort -r |pr -d > /etc/hosts
what would be the expected outcome? I know lowercase 'a' would change to uppercase 'A' but what's next? Would the original file ...
- 101
10
votes
3
answers
4k
views
tr analog for unicode characters?
I need internationalized utility that does the same thing as tr: gets character from stream and substitutes it with a corresponding character.
Not a particular case solution like lower-to-upper, but a ...
- 123
10
votes
2
answers
7k
views
Is there any way to use the tr command in place?
I want to remove all non-english alphanumerals from a file.
tr -sc '[:alnum:][:punct:]' ' ' <file
gawk and sed have the -i flag but I cannot find anything similar in the tr man pages.
How can I ...
user199046
10
votes
2
answers
8k
views
Removing non printable characters from expect logs?
How can I either strip the following character sequences from my files? ^[[64;8H, ^[[?25h, ^[[1;64r etc or avoid having expect add them in the first place?
Background:
I'm using a collection of ...
- 1,017
9
votes
2
answers
3k
views
Explanation needed on how I can repeat a character in POSIX shell
The following answer on Stack Overflow,
How can I repeat a character in bash?
imposes one plausible way of POSIX-ly repeating a single character, as follows. In this example let's use the equal sign ...
- 27.8k
8
votes
2
answers
3k
views
Why doesn't the command tr "\'\\\"\?\!" "01234" work?
In terminal, if I define some variable char as follows:
export char=\'\\\"\?\!
In effect, char is the string
'\"?!
And then I use the tr command to replace '\"?! with numbers 01234
tr "\'\\\"\?\!"...
- 81
8
votes
4
answers
10k
views
how to use tr to replace multiple sets?
I want to use tr to replace digits 0-5 with A and digits 6-9 with B.
I tried using sed to do this:
sed 's/[0-4]/</; s/[6-9]/>/'
It works only once though so for example if I write 123 it will ...
- 89
7
votes
9
answers
11k
views
Replace any number of tabs and spaces with single new line in Linux?
Suppose I have a (potentially very large) text file
that contains a word list with whitespace interjected.
For example, it might look like this:
Cat Dog
Soup ...
- 81
7
votes
1
answer
632
views
Is it possible to replace duplicates of a character with one character using tr
I'm trying to take all occurrences of # and if they are consecutive replace them with just one #.
e.g.
ab ### cde fghi## jklm
would become:
ab # cde, fghi# jklm
My initial goal was to replace ...
- 79
7
votes
2
answers
13k
views
Redirecting tr stdout to a file [duplicate]
Possible Duplicate:
How can I make iconv replace the input file with the converted output?
Can I read and write to the same file in Linux without overwriting it?
$ cat test.txt
This is a test ...
- 1,027
7
votes
2
answers
629
views
Escape characters in sed transliterate
I want to use sed's transliterate (y///) to replace one set of characters by another.
I would expect this to work just as well as using the tr program.
$ echo '[]{}abc' | tr '[ab}' 'gefh'
g]{hefc
...
- 174
7
votes
4
answers
7k
views
Is the command tr capable of translating characters into longer strings?
tr is a great tool that can be used to translate set of characters into another set of characters.
Commands such as sed , awk, perl can be used to translate set of characters into another set of ...
user4518
6
votes
3
answers
3k
views
How do I use tr command to replace: full stops, exclamations and question marks followed by a space, with newlines?
I have text that goes like this:
I am happy. I am here. How are you, Meg?
I want this to be:
I am happy.
I am here.
How are you, Meg?
For full stops I tried
tr -s '. ' '\n' <file.txt >out....
user199046
6
votes
1
answer
19k
views
Delete only first occurrence of character using tr
I want to delete the occurrence of a character in a string only for the first occurrence.
Example:
echo "B123_BACK" | tr -d 'B'
This results in output:
123_ACK
How can I delete only the first ...
- 1,724
6
votes
6
answers
5k
views
How to change any text to Proper Case and Sentence case using tr?
According to https://caseconverter.com/
“Upper Case” WHICH CONVERTS ALL THE LETTER INTO CAPITALS LIKE THIS.
“Lower Case” which converts all the letters into small letters like
this.
“...
user264359
6
votes
1
answer
311
views
Heirloom Toolchest tr: error(s) trying to delete the complement of a set containing a multibyte character?
I'm trying to use the tr command from the Heirloom Toolchest to overcome a current limitation of the coreutils implementation, so as to be able to "pump" (with the -dc options) multibyte characters ...
user44370
6
votes
1
answer
3k
views
How do I turn accented lowercase letters to uppercase? - Using the 'tr' command [duplicate]
I'm tryed with:
$ echo 'Ciência' | tr 'a-z' 'A-Z'
CIêNCIA
But the 'ê' character does not change, obviously because it is accentuated.
Then I tried with POSIX classes:
echo "Ciência" | tr '[:lower:]'...
- 765
5
votes
5
answers
1k
views
How can I transliterate some characters 1-to-1, leave some unchanged, and replace others with the same target character?
I have a file called file.txt containing:
MAL TIRRUEZF CR MAL RKZYIOL EX MAL OIY UAE RICF "MAL ACWALRM DYEUPLFWL CR ME DYEU MAIM UL IZL RKZZEKYFLF GH OHRMLZH"
I'd like the characters ...
user493569
5
votes
3
answers
1k
views
how to emulate "replace a b b a" with a sed?
I am trying to emulate a replace command which swaps two characters, with a sed script,
but the obvious choice:
sed -e 's/a/b/g' -e 's/b/a/g'
does no work. Can you point me how to do it correctly?
- 373
5
votes
1
answer
306
views
Why does 'tr' with '-c' option and set 2 extension add an unwarranted character to the end?
I wanted to use tr to substitute "illegal" characters in a string with a replacement character, where "illegal" characters are all outside of a set of "allowed" ...
- 21.8k
5
votes
3
answers
304
views
Processing a continuous single line of data with stream processing in bash pipeline?
I am debugging an embedded server that outputs a continuous single line of text to a specified network port. There is no newline anywhere in the stream but it is text data and I would like to format ...
- 193
5
votes
1
answer
239
views
Debian wheezy updates broke tr command [closed]
After I updated the following packages yesterday in debian wheezy, tr command stop working.
Start-Date: 2016-02-16 23:10:06
Commandline: apt-get dist-upgrade
Upgrade: libkrb5-3:amd64 (1.10.1+dfsg-5+...
- 1,494
5
votes
2
answers
4k
views
what is the benefit of --squeeze-repeats in tr command
What is the benefit of -s or --squeeze-repeats when we use tr? What practical usage?
- 3,018
4
votes
3
answers
19k
views
Pulling IP address from ping command with sed? [duplicate]
I have crafted a Bash tool that runs on a server. This tool will block certain IP addresses for a certain time range (i.e. from 5 A.M. to 3:30 P.M.).
As of currently, the tool works fine, but I have ...
- 223
4
votes
4
answers
2k
views
How do I delete all lines with ".png" in a file?
I've a list of urls of which some point to images:
http://s.thebrighttag.com/iframe?c=A5lqOqP
http://s.wordpress.com/imgpress?resize=136,136&url=http%3A%2F%2Fdata.whicdn.com%2Fimages%...
- 611
4
votes
6
answers
6k
views
Linux tr to convert vertical text to horizontal
I've been reading about https://stackoverflow.com/questions/39791042/convert-vertical-text-into-horizontal-in-shell
and wondering if tr alone can be used to convert vertical text to horizontal.
user@...
user264359
4
votes
4
answers
5k
views
How does "-dc" work in "cat /dev/urandom | tr -dc "01"?
So far I know,
the /dev/urandom file is one of the special files, it's purpose is to generate random characters.
When I execute cat /dev/urandom a stream of strange characters, some even Chinese ...
- 25.9k
4
votes
6
answers
203
views
Make longer strings from substrings keeping new line between each string
I have a file that contains strings as:
GTACGACGGAGTGTTATAAGATGGGAAATCGGATACCAGATGAAATTGTGGATCGGTGCAAAA
GTCGGCAGATATCGTTGAAGTCATAGGTGATTATGTTCAATTAAAGAAGCAAGGCCGAAACTAC
...
- 135