ax-common.sh: Only use colors when writing to a terminal

diff --git a/lib/ax/ax-common.sh b/lib/ax/ax-common.sh
index e51f81616b14775ca2e5b2ad14c121f351d5da36..c0362ffd755e282c3435910c534b5371622bf93b 100644 (file)
--- a/lib/ax/ax-common.sh
+++ b/lib/ax/ax-common.sh
@@ -14,20 +14,26 @@
 # shellcheck disable=SC2034
 ax_common_sourced=2
 
-# Display a colored message.
+# Display a colored message (a plain message, when not writing to a terminal).
 #  $1    Level: -=title, 0=ok, 1=warning, 2=error.
 #  $2    Word(s) to highlight.
 #  $3-n  Remaining word(s). [optional]
 ax_msg1() {
-       case "$1" in
-               "0")    c="32"; shift; ;;       # green
-               "1")    c="33"; shift; ;;       # yellow
-               "2")    c="31"; shift; ;;       # red
-               "-")    c="1";  shift; ;;       # bold
-               *)      c="0";
-       esac
-       # print colored word(s):
-       printf "\033[0;%sm%s\033[0m " "${c}" "${1}"
+       if [ -t 1 ]; then
+               # writing to a terminal ...
+               case "$1" in
+                       "0")    c="32"; shift; ;;       # green
+                       "1")    c="33"; shift; ;;       # yellow
+                       "2")    c="31"; shift; ;;       # red
+                       "-")    c="1";  shift; ;;       # bold
+                       *)      c="0";
+               esac
+               # print colored word(s):
+               printf "\033[0;%sm%s\033[0m " "${c}" "${1}"
+       else
+               # print plain text:
+               printf "%s " "${1}"
+       fi
        shift
        # print remaining word(s) and trailing newline:
        echo "${*}"