cli: additionalHelp() don't decorate output if it's piped

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/ESC
    https://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>
This commit is contained in:
Sebastiaan van Stijn 2022-04-01 12:25:55 +02:00
parent d0a4b6f497
commit 59e74b44ae
No known key found for this signature in database
GPG Key ID: 76698F39D527CE8C
1 changed files with 6 additions and 2 deletions

View File

@ -234,9 +234,13 @@ func isExperimental(cmd *cobra.Command) bool {
}
func additionalHelp(cmd *cobra.Command) string {
if additionalHelp, ok := cmd.Annotations["additionalHelp"]; ok {
if msg, ok := cmd.Annotations["additionalHelp"]; ok {
out := cmd.OutOrStderr()
if _, isTerminal := term.GetFdInfo(out); !isTerminal {
return msg
}
style := aec.EmptyBuilder.Bold().ANSI
return style.Apply(additionalHelp)
return style.Apply(msg)
}
return ""
}