testing gnu grep 2.5.1 for matching leading unescaped curly braces

gistfile1.txt

sparr$ grep --version
grep (GNU grep) 2.5.1

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sparr$ echo "foo { bar" | grep "{"
foo { bar
sparr$ echo "foo { bar" | grep -E "{"
foo { bar
sparr$ echo "foo { bar" | grep -E "\{"
foo { bar
sparr$ echo "foo { bar" | grep -o "{"
{
sparr$ echo "foo { bar" | grep -Eo "{"
{
sparr$ echo "foo { bar" | grep -Eo "\{"
{
sparr$ echo "foo { bar" | grep -o "{" | wc
       1       1       2
sparr$ echo "foo { bar" | grep -Eo "{" | wc
       1       1       2
sparr$ echo "foo { bar" | grep -Eo "\{" | wc
       1       1       2