How can processes eliminate escape codes when its output is piped?
bool3max
That's a pretty weird title but I'm having trouble articulating this question:
When I run kitty --version in my terminal it prints its version out to stdout, however the text is styled and colored:
In order to achieve this the process had to output ANSI escape codes to stdout, however I don't see them when I hexdump the output:
$ kitty --version | xxd -g 1 -c 10 -u
00000000: 6B 69 74 74 79 20 30 2E 31 39 kitty 0.19
0000000a: 2E 31 20 63 72 65 61 74 65 64 .1 created
00000014: 20 62 79 20 4B 6F 76 69 64 20 by Kovid
0000001e: 47 6F 79 61 6C 0A Goyal.
I'd expect to see at least a few escape characters and other ANSI sequences here but I don't. This leads me to believe that kitty is able to "predict" whether its output will appear in a terminal that can process the escape codes.
How is it able to do that? Or is it a feature of the terminal emulator perhaps?
waltinator
Read man isatty, or https://linux.die.net/man/3/isatty
isatty - test whether a file descriptor refers to a terminal
Collected from the Internet
Please contact [email protected] to delete if infringement.
edited at
Related
Related Related
- 1
How can I kill piped background processes?
- 2
How can I kill piped background processes?
- 3
How does a program output to a terminal when stdout is piped?
- 4
Program output changes when piped
- 5
How to generate sql output as piped
- 6
How can I tell Vim to show ANSI escape codes properly?
- 7
How can we escape the folder name having space in its name when passed from variable ?
- 8
Why does make ignore escape sequence if the output is piped
- 9
How can I get python ''.encode('unicode_escape') to return escape codes for ascii?
- 10
How can htop be used to suspend a process and all its child processes?
- 11
Stop grep from parsing its own output piped to file
- 12
How can the convert command's output be passed/piped instead of saved to a file?
- 13
Can an object tell Twig not to escape output when it is {{ printed }}
- 14
How to format piped output in powershell to a line
- 15
Where do my ANSI escape codes go when I pipe to another process? Can I keep them?
- 16
How can I simplify the codes without affect the output?
- 17
How can I test if the output of my program contains color (codes)?
- 18
php: how can a similar codes results different output?
- 19
How to reverse escape output
- 20
How to reverse escape output
- 21
How can I truncate a string to a maximum length without breaking ANSI escape codes
- 22
How can I tell echo/printf in Bash to swallow escape codes, based on a condition?
- 23
How can I truncate a string to a maximum length without breaking ANSI escape codes
- 24
How can I read redirected/piped data?
- 25
How can a conditional statement be used in a piped command?
- 26
Why don't some "for" commands work when the output is piped?
- 27
ag output appears different in the terminal vs when piped to a file
- 28
Why does bash output data instead of executing, when a script is piped?
- 29
Why won't journalctl show logs when the program output is piped?
Comments