diff --git a/tools/check-style.sh b/tools/check-style.sh
index b87cb16e..050482da 100755
--- a/tools/check-style.sh
+++ b/tools/check-style.sh
@@ -19,10 +19,10 @@ errors=0
 IFS=$'\n'
 found=
 # The mt=41 sets a red background for matched tabs:
-exec 3< <(GREP_COLORS='mt=41' grep $'\t' include/ tests/*.{cpp,py,h} docs/*.rst -rn --color=always)
-while read -u 3 f; do
+GREP_COLORS='mt=41' GREP_COLOR='41' grep $'\t' include tests/*.{cpp,py,h} docs/*.rst -rn --color=always |
+        while read f; do
     if [ -z "$found" ]; then
-        echo -e '\e[31m\e[01mError: found tabs instead of spaces in the following files:\e[0m'
+        echo -e '\033[31m\033[01mError: found tabs instead of spaces in the following files:\033[0m'
         found=1
         errors=1
     fi
@@ -31,11 +31,10 @@ while read -u 3 f; do
 done
 
 found=
-# The mt=41 sets a red background for matched MS-DOS CRLF line endings
-exec 3< <(GREP_COLORS='mt=41' grep -IUlr $'\r' include/ tests/*.{cpp,py,h} docs/*.rst --color=always)
-while read -u 3 f; do
+grep -IUlr $'\r' include tests/*.{cpp,py,h} docs/*.rst --color=always |
+        while read f; do
     if [ -z "$found" ]; then
-        echo -e '\e[31m\e[01mError: found CRLF characters in the following files:\e[0m'
+        echo -e '\033[31m\033[01mError: found CRLF characters in the following files:\033[0m'
         found=1
         errors=1
     fi
@@ -45,10 +44,10 @@ done
 
 found=
 # The mt=41 sets a red background for matched trailing spaces
-exec 3< <(GREP_COLORS='mt=41' grep '\s\+$' include/ tests/*.{cpp,py,h} docs/*.rst -rn --color=always)
-while read -u 3 f; do
+GREP_COLORS='mt=41' GREP_COLOR='41' grep '[[:blank:]]\+$' include tests/*.{cpp,py,h} docs/*.rst -rn --color=always |
+        while read f; do
     if [ -z "$found" ]; then
-        echo -e '\e[31m\e[01mError: found trailing spaces in the following files:\e[0m'
+        echo -e '\033[31m\033[01mError: found trailing spaces in the following files:\033[0m'
         found=1
         errors=1
     fi
@@ -57,10 +56,10 @@ while read -u 3 f; do
 done
 
 found=
-exec 3< <(grep '\<\(if\|for\|while\|catch\)(\|){' include/ tests/*.{cpp,py,h} -rn --color=always)
-while read -u 3 line; do
+grep '\<\(if\|for\|while\|catch\)(\|){' include tests/*.{cpp,py,h} -rn --color=always |
+        while read line; do
     if [ -z "$found" ]; then
-        echo -e '\e[31m\e[01mError: found the following coding style problems:\e[0m'
+        echo -e '\033[31m\033[01mError: found the following coding style problems:\033[0m'
         found=1
         errors=1
     fi
@@ -69,10 +68,10 @@ while read -u 3 line; do
 done
 
 found=
-exec 3< <(GREP_COLORS='mt=41' grep '^\s*{\s*$' include/ docs/*.rst -rn --color=always)
-while read -u 3 f; do
+GREP_COLORS='mt=41' GREP_COLOR='41' grep '^\s*{\s*$' include docs/*.rst -rn --color=always |
+        while read f; do
     if [ -z "$found" ]; then
-        echo -e '\e[31m\e[01mError: braces should occur on the same line as the if/while/.. statement. Found issues in the following files: \e[0m'
+        echo -e '\033[31m\033[01mError: braces should occur on the same line as the if/while/.. statement. Found issues in the following files: \033[0m'
         found=1
         errors=1
     fi