This prevents the escape-characters being included when piping the
output, e.g. `docker --help > output.txt`, or `docker --help | something`.
These control-characters could cause issues if users copy/pasted the URL
from the output, resulting in them becoming part of the URL they tried
to visit, which would fail, e.g. when copying the output from:
To get more help with docker, check out our guides at https://docs.docker.com/go/guides/
Users ended up on URLs like;
https://docs.docker.com/go/guides/ESChttps://docs.docker.com/go/guides/%1B[0m
Before this patch, control characters ("bold") would be printed, even if
no TTY was attached;
docker --help > output.txt
cat output.txt | grep 'For more help' | od -c
0000000 033 [ 1 m F o r m o r e h e l
0000020 p o n h o w t o u s e
0000040 D o c k e r , h e a d t o
0000060 h t t p s : / / d o c s . d o c
0000100 k e r . c o m / g o / g u i d e
0000120 s / 033 [ 0 m \n
0000127
docker --help | grep 'For more help' | od -c
0000000 033 [ 1 m F o r m o r e h e l
0000020 p o n h o w t o u s e
0000040 D o c k e r , h e a d t o
0000060 h t t p s : / / d o c s . d o c
0000100 k e r . c o m / g o / g u i d e
0000120 s / 033 [ 0 m \n
0000127
With this patch, no control characters are included:
docker --help > output.txt
cat output.txt | grep 'For more help' | od -c
0000000 F o r m o r e h e l p o n
0000020 h o w t o u s e D o c k
0000040 e r , h e a d t o h t t p
0000060 s : / / d o c s . d o c k e r .
0000100 c o m / g o / g u i d e s / \n
0000117
docker --help | grep 'For more help' | od -c
0000000 F o r m o r e h e l p o n
0000020 h o w t o u s e D o c k
0000040 e r , h e a d t o h t t p
0000060 s : / / d o c s . d o c k e r .
0000100 c o m / g o / g u i d e s / \n
0000117
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 59e74b44ae)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
1686805f63