Added tesseract version and libcurl check for URL input

.github/workflows/ci.yaml

@@ -41,7 +41,7 @@ jobs:
         run: echo "PY=$(python -VV | sha256sum | cut -d' ' -f1)" >> $GITHUB_ENV
 
       - name: Install tesseract
-        run: sudo apt-get -y update && sudo apt-get install -y tesseract-ocr tesseract-ocr-fra
+        run: sudo apt-get -y update && sudo apt-get install -y libcurl4-openssl-dev tesseract-ocr tesseract-ocr-fra
 
       - name: Print tesseract version
         run: echo $(tesseract --version)

pytesseract/pytesseract.py

@@ -81,6 +81,7 @@
 
 TESSERACT_MIN_VERSION = Version('3.05')
 TESSERACT_ALTO_VERSION = Version('4.1.0')
+TESSERACT_URL_VERSION = Version('4.1.1')
 
 
 class Output:
@@ -123,6 +124,12 @@ def __init__(self):
             'ALTO output not supported. Tesseract >= 4.1.0 required',
         )
 
+class URLNotSupported(EnvironmentError):
+    def __init__(self):
+        super().__init__(
+            'URL input not supported. Tesseract >= 4.1.1 and libcurl required',
+        )
+
 
 def kill(process, code):
     process.terminate()
@@ -210,6 +217,9 @@ def save(image):
         with NamedTemporaryFile(prefix='tess_', delete=False) as f:
             if isinstance(image, str):
                 if image.startswith('http:') or image.startswith('https:'):
+                    if get_tesseract_version(cached=True) < TESSERACT_URL_VERSION\
+                        or not has_libcurl(cached=True):
+                        raise URLNotSupported()
                     yield f.name, image
                 else:
                     yield f.name, realpath(normpath(normcase(image)))
@@ -473,6 +483,24 @@ def get_tesseract_version():
     return version
 
 
+@run_once
+def has_libcurl():
+    """
+    Returns True if tesseract-ocr was installed with libcurl or False otherwise
+    """
+    try:
+        output = subprocess.check_output(
+            [tesseract_cmd, '--version'],
+            stderr=subprocess.STDOUT,
+            env=environ,
+            stdin=subprocess.DEVNULL,
+        )
+    except OSError:
+        raise TesseractNotFoundError()
+
+    return 'libcurl' in output.decode(DEFAULT_ENCODING)
+
+
 def image_to_string(
     image,
     lang=None,