Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [escape-characters]

Escape sequences such as encodings of terminal commands and function keys

112
votes
2answers
9k views

Is Vim immune to copy-paste attack?

You should never paste from web to your terminal. Instead, you should paste to your text editor, check the command and then paste to the terminal. That's OK, but what if Vim is my text editor? Could ...
64
votes
10answers
40k views

Removing control chars (including console codes / colours) from script output

I can use the "script" command to record an interactive session at the command line. However, this includes all control characters and colour codes. I can remove control characters (like backspace) ...
61
votes
2answers
82k views

Why does Ctrl-D (EOF) exit the shell?

Are you literally "ending a file" by inputting this escape sequence, i.e. is the interactive shell session is seen as a real file stream by the shell, like any other file stream? If so, which file? ...
58
votes
10answers
67k views

How do I clear the Gnome terminal history?

When we use clear command or Ctrl+L in terminal, it clears terminal but we can still scroll back to view the last used commands. Is there a way to completely clear the terminal?
58
votes
5answers
153k views

How to escape quotes in shell?

I'm having trouble with escaping characters in bash. I'd like to escape single and double quotes while running a command under a different user. For the purposes of this question let's say I want to ...
40
votes
3answers
23k views

Where do I find a list of terminal key codes to remap shortcuts in bash?

For example: "\e[1;5C" "\e[Z" "\e-1\C-i" I only know bits and pieces, like \e stands for escape and C- for Ctrl, but what are these numbers (1) and letters (Z)? What are the ;, [ and - signs for? ...
35
votes
3answers
2k views

How do some tools (e.g. nano , less) manage to leave no content in terminals after exit? [duplicate]

Whenever I use a pager like less or an editor like nano in the shell (my shell is GNU bash), I see a behaviour I cannot explain completely and which differs to the behaviour I can observe with other ...
34
votes
2answers
6k views

Where do my ANSI escape codes go when I pipe to another process? Can I keep them?

I sometime want to pipe the color-coded output fror a process, eg. grep... but when I pipe it to another process, eg. sed, the color codes are lost... Is the some way to keep thes codes intact ? ...
30
votes
4answers
64k views

How to make the terminal display user@machine in bold letters?

I have seen in some screen-shots (can't remember where on the web) that the terminal can display the [username@machine /]$ in bold letters. I'm looking forward to getting this too because I always ...
29
votes
6answers
24k views

Is there any reason why I get ^[[A when I press up arrow at the console login screen?

Whenever I'm at the console login, I press up arrow intentionally to see the previously typed commands. But I see this ^[[A. But when I press Ctrl Alt Print Screen Scroll Lock Pause Break Page Up ...
29
votes
2answers
6k views

How to avoid escape sequence attacks in terminals?

Reading the details of CVE-2009-4487 (which is about the danger of escape sequences in log files) I am a bit surprised. To quote CVE-2009-4487: nginx 0.7.64 writes data to a log file without ...
23
votes
3answers
2k views

How to prevent random console output from breaking the terminal?

There are many questions on SE that show how to recover from terminal broken by cat /dev/urandom. For those that are unfamiliar with this issue - here what it is about: You execute cat /dev/urandom ...
22
votes
4answers
10k views

Make Less highlight search patterns instead of italicizing them

To my understanding man uses less as a pager, and when searching for keywords using less it "highlights" keywords with italics. I find that really inconvenient, so I'd like to change this to something ...
19
votes
3answers
67k views

Escape sequences with “echo -e” in different shells

I just noticed that it seems like the flag -e does not exist for the echo command in my shell on Linux. Is this just a messed up setting or is it "normal"? Some code as an example: #!/bin/sh echo -e ...
19
votes
2answers
2k views

How do I use grep while keeping the original text color? [duplicate]

For example, I have a output: Hello, this is the output. (let's say that for example hello is colored red, and the is colored green, and output is colored purple). Now, let's say that this is the ...
15
votes
7answers
2k views

How can I count the number of times a byte sequence occurs in a file?

I want to count how many times a certain sequence of bytes happens inside a file that I have. For example, I want to find out how many times the number \0xdeadbeef occurs inside an executable file. ...
14
votes
4answers
2k views

Escape sequences in output of script called from ncurses application

I'm currently running mcabber as my Jabber client (which uses ncurses) in a tmux session on my homeserver. Locally i run iTerm2 as a terminal emulator, which supports the triggering of growl ...
13
votes
2answers
4k views

How do I background an SSH session? [duplicate]

Possible Duplicate: How can I break away from an SSH session that has crashed? I have started an SSH session on the command line, but now I want to get back to my local command line. For any ...
13
votes
1answer
5k views

Caret square bracket square bracket A ^[[A - What does it mean?

Apologies if this has already been asked, but I have no idea how I can find this out myself - when I search for "^[[A" in any search engine it ignores the "^[[" part altogether. Anyway, my question: ...
12
votes
1answer
2k views

Weird symbols on screen when using grep?

Any idea what could be causing this? Without using grep, the only stuff display there are the ISO codes and empty space. Software used Command: ./trans --id --input /path/to/txt | grep ISO | grep [a-...
12
votes
1answer
15k views

Why do I have to escape a “dot” twice?

I know that we can escape a special character like *(){}$ with \ so as to be considered literals. For example \* or \$ But in case of . I have to do it twice, like \\. otherwise it is considered ...
12
votes
2answers
5k views

The difference between \e and ^[

Gilles wrote: character 27 = 033 = 0x1b = ^[ = \e Demizey wrote: ^[ is just a representation of ESCAPE and \e is interpreted as an actual ESCAPE character Then I also found this line from a ...
12
votes
2answers
5k views

How to determine the current color of the console output?

I know that, if a coloured terminal is available, one can colour the output of it using escape characters. But is there a possibility to find out, which colour the output is currently being displayed ...
10
votes
6answers
14k views

How can I create a file with multiple lines from the command-line? [duplicate]

How can I enter the following contents in a file: Hi abcd I tried using echo "Hi\nabcd" >> ab.txt, but in the file it's written as is (the \n is included, instead of a newline)
10
votes
2answers
19k views

Trouble in script with spaces in filename

I've got a script that scp's a file from remote host back to local. Sometimes the file names contain spaces. scp does not like spaces in its file names. For some reason my attempts at handling the ...
10
votes
2answers
15k views

How to escape < or > in a parameter in shell?

I'd like to use grep with a PCRE expression that contains the < character. Bash thinks I want to redirect, but I don't want to. How can I escape <?
10
votes
1answer
378 views

Do shells other than Bash and Zsh support ANSI-C quoting? e.g. $'string'

I have a shell script that uses the following to print a green checkmark in its output: col_green="\e[32;01m" col_reset="\e[39;49;00m" echo -e "Done ${col_green}✓${col_reset}" After reading about ...
9
votes
2answers
2k views

What is the gnome-terminal ANSI escape sequence for “CTRL + arrow/s”?

I am trying to configure my bash ~/.inputrc to these settings (Note: ←, → mean the left and right arrow keys) Ctrl + ← - should jump back a word Ctrl + → - should jump forward a word Currently I ...
9
votes
4answers
1k views

is there a pastebin service that supports terminal escape sequences?

Is there a pastebin service that supports colors? I understand some of them have syntax hilighting, but I'd like to do arbitrary coloring, preferably using the terminal escape sequences. For example, ...
9
votes
3answers
1k views

Is there any objective benefit to escape sequences over tput?

In people's '.*rc' files I see online or in various code, I tend to see a lot of people who manually use ANSI escape sequences instead of using tput. I had the understanding that tput is more ...
8
votes
3answers
19k views

export HTTP_PROXY and special characters in passwd

Suppose for the sake of argument my password below is abc123@ I need to authenticate my linux machine through a corporate proxy to get patches and updates... normally I'd use this: export HTTP_PROXY=...
8
votes
3answers
5k views

How to print control characters with escape sequences?

I have defined the color red using tput red=$(tput setaf 1) to colorize warnings in my program. This works fine: printf '%sfail\n' "$red" # prints 'fail' in red But on one occasion I would like to ...
8
votes
1answer
3k views

Visualizing ansi color escape codes in log files correctly in Emacs [duplicate]

I have some log files that have ansi-color codes in them. When I open them in Emacs I see garbage:           As an example, I run the following: ls --color=yes -ald -- * &...
8
votes
2answers
777 views

DEC ANSI command sequence questions; cursor movement

So I'm writing a terminal emulation (I know, I should just compile putty, etc.) and am at the stage of plodding through vttest to make sure it's right. I'm basing it on the VT102 for now but will add ...
7
votes
1answer
4k views

How to use less in a script without getting ESC escape characters?

When I use less at the command line the output is like but when I use less from within a bash script I get: How can I use less in a bash script and not get all the escape characters and have it work ...
7
votes
2answers
7k views

Change colors in console/virtual terminal

Is there a way to alter all the available colors in console / virtual terminal? By console, I mean what you get after pressing CTRL + ALT + F1 and not anything like xterm or urxvt. So, I guess that ...
7
votes
2answers
2k views

Issue with column command and color escape codes

I'm colorizing the header of a table formatted with column -ts $'\t' Works well without color codes, but when I add color codes to the first line column doesn't properly align the output. Without ...
7
votes
1answer
4k views

Hide and unhide cursor with tput

tput civis successfully hides the cursor. tput cvvis should unhide it, but it doesn't. Any idea what the problem might be?
6
votes
2answers
4k views

Is it possible to use ANSI color escape codes in Bash here-documents?

I'm printing a message in a Bash script, and I want to colourise a portion of it; for example, #!/bin/bash normal='\e[0m' yellow='\e[33m' cat <<- EOF ${yellow}Warning:${normal} This script ...
6
votes
1answer
240 views

Escape a mm/dd/YY backup date in a file name

I have been trying to: cp file.csv file.$(date +%D).csv But it fails because the filenames is: file.03/27/19.csv with the slash of separate directories. And I have been trying again to: cp file....
6
votes
5answers
13k views

What is the problem with the output of plink?

On my Windows7 machine, I'm traversing to the installed path of PuTTy Application and running: plink <hostname> to connect to my remote Linux host. I see some unrecognized characters in the ...
6
votes
4answers
11k views

Null and escape characters

I know that a filename in Linux has no restriction whatsoever except for two characters '/' and '\0'. I know that '/' is prohibited because it is a directory separator but is there any other reason ? ...
6
votes
2answers
5k views

Passing a bash command-line argument containing a dot

How can a command-line argument containing a dot (.) be passed? Are there any escape sequences for capturing characters like dot? The following invocation of a bash-script from the shell does not ...
6
votes
1answer
2k views

How to find out the escape sequence my keyboards sends to terminal?

Let's say we have a generic keyboard with some unknown keys which may send escape sequences to terminal. The keyboard is connected to an xterm terminal emulator running on a generic BSD/Linux. To ...
6
votes
1answer
2k views

Where is the character escape sequence `\033[\061m` documented to mean bold?

I am trying to write a program that runs a console program like gcc and displays its output in color. I used openpty instead of pipe to pretend to be a character device and now get ANSI escape codes ...
6
votes
3answers
2k views

Non-printing escape sequence: when?

Recently, I have been playing around a lot with color in the terminal and, therefore, with escape sequences, too. I've read the relevant parts of the Bash manpage along with numerous helpful pages on ...
6
votes
1answer
6k views

How can I match the page break character in a regular expression?

Nano calls it ^L, but of course, typing something like $ grep -v "^\^L" file doesn't work. Its unicode codepoint is 000C. How can I match it in a regular expression?
6
votes
2answers
1k views

Terminal escape sequences: why don't terminals report what features they support, instead of relying on terminfo?

I've been looking into escape sequences lately, and I'm surprised of what they can do. You can even move an xterm X11 window with them (try printf '\e[3;0;0t'), wow! The most common way to know what ...
6
votes
1answer
5k views

In Bash, why is PROMPT_COMMAND set to something invisible?

On RHEL6 and CentOS 6, /etc/bashrc sets PROMPT_COMMAND here: case $TERM in xterm*) if [ -e /etc/sysconfig/bash-prompt-xterm ]; then PROMPT_COMMAND=/etc/sysconfig/bash-prompt-xterm ...
6
votes
2answers
1k views

Reverse control-code look up for terminals

My understanding is that terminals often use ANSI control-codes to represent non-alphanumeric character sequences. For example, when editing .inputrc for Bash in Linux, it's easy to find code ...