Linux Dev:Detecting output type

More work. Also updated style.css to support terminal styles for
paragraphs as well as pre.

1 files changed, 36 insertions, 8 deletions

diff --git a/src/linux_development:detecting_output_type.ascii b/src/linux_development:detecting_output_type.ascii
index a2954ec..792ee3d 100644
--- a/src/linux_development:detecting_output_type.ascii
+++ b/src/linux_development:detecting_output_type.ascii
@@ -19,19 +19,21 @@ For example, a script like this...
 ----
 #!/usr/bin/env bash
 
-echo -e "[\e[32mINFO\e[0m]  This is a useful info message."
-echo -e "[\e[33mWARN\e[0m]  This is an ominous warning message."
-echo -e "[\e[31mERROR\e[0m] This is a scary error message."
+echo -e "[ \e[32mINFO\e[0m ]  This is a useful info message."
+echo -e "[ \e[33mWARN\e[0m ]  This is an ominous warning message."
+echo -e "[ \e[31mERROR\e[0m ] This is a scary error message."
 ----
 
 Outputs something like this in the terminal
 
 [role="terminal"]
-____
-\[[green]#INFO#]  This is a useful info message.
-\[[yellow]#WARN#]  This is an ominous warning message.
-\[[red]#ERROR#] This is a scary error message.
-____
+====
+[ [green]#INFO# ]  This is a useful info message.
+
+[ [yellow]#WARN# ]  This is an ominous warning message.
+
+[ [red]#ERROR# ] This is a scary error message.
+====
 
 
 ...But something like this when piped to less
@@ -44,6 +46,32 @@ ____
 ----
 
 
+As you can see, the escape codes are sent verbatim to the program on the other
+side of the pipe. If it doesn't properly render them by default (which newer
+versions of gnu less do now), you'll see those escape codes on your output.
+This is particularly annoying in the cases of log files. The same behavior
+comes out if the output stream is redirected into a file.
+
+So how do we detect that the end user has redirected output with a pipe or a
+redirection so we can remove the escape codes and just ouput plain text?
+
+
+The Solution
+------------
+
+Bash provides this really useful 'if switch', *-t*. From the bash man page...
+
+[quote, Bash(1)]
+____
+  -t fd  True if file descriptor fd is open and refers to a terminal.
+____
+
+Let's give this a try.
+
+
+
+
+
 
 :revdate: June 29, 2016
 [role="datelastedit"]