mirror of https://github.com/python/cpython
161 lines
3.6 KiB
Python
161 lines
3.6 KiB
Python
"""Recognize image file formats based on their first few bytes."""
|
|
|
|
__all__ = ["what"]
|
|
|
|
#-------------------------#
|
|
# Recognize image headers #
|
|
#-------------------------#
|
|
|
|
def what(file, h=None):
|
|
f = None
|
|
try:
|
|
if h is None:
|
|
if isinstance(file, str):
|
|
f = open(file, 'rb')
|
|
h = f.read(32)
|
|
else:
|
|
location = file.tell()
|
|
h = file.read(32)
|
|
file.seek(location)
|
|
for tf in tests:
|
|
res = tf(h, f)
|
|
if res:
|
|
return res
|
|
finally:
|
|
if f: f.close()
|
|
return None
|
|
|
|
|
|
#---------------------------------#
|
|
# Subroutines per image file type #
|
|
#---------------------------------#
|
|
|
|
tests = []
|
|
|
|
def test_jpeg(h, f):
|
|
"""JPEG data in JFIF or Exif format"""
|
|
if h[6:10] in (b'JFIF', b'Exif'):
|
|
return 'jpeg'
|
|
|
|
tests.append(test_jpeg)
|
|
|
|
def test_png(h, f):
|
|
if h.startswith(b'\211PNG\r\n\032\n'):
|
|
return 'png'
|
|
|
|
tests.append(test_png)
|
|
|
|
def test_gif(h, f):
|
|
"""GIF ('87 and '89 variants)"""
|
|
if h[:6] in (b'GIF87a', b'GIF89a'):
|
|
return 'gif'
|
|
|
|
tests.append(test_gif)
|
|
|
|
def test_tiff(h, f):
|
|
"""TIFF (can be in Motorola or Intel byte order)"""
|
|
if h[:2] in (b'MM', b'II'):
|
|
return 'tiff'
|
|
|
|
tests.append(test_tiff)
|
|
|
|
def test_rgb(h, f):
|
|
"""SGI image library"""
|
|
if h.startswith(b'\001\332'):
|
|
return 'rgb'
|
|
|
|
tests.append(test_rgb)
|
|
|
|
def test_pbm(h, f):
|
|
"""PBM (portable bitmap)"""
|
|
if len(h) >= 3 and \
|
|
h[0] == ord(b'P') and h[1] in b'14' and h[2] in b' \t\n\r':
|
|
return 'pbm'
|
|
|
|
tests.append(test_pbm)
|
|
|
|
def test_pgm(h, f):
|
|
"""PGM (portable graymap)"""
|
|
if len(h) >= 3 and \
|
|
h[0] == ord(b'P') and h[1] in b'25' and h[2] in b' \t\n\r':
|
|
return 'pgm'
|
|
|
|
tests.append(test_pgm)
|
|
|
|
def test_ppm(h, f):
|
|
"""PPM (portable pixmap)"""
|
|
if len(h) >= 3 and \
|
|
h[0] == ord(b'P') and h[1] in b'36' and h[2] in b' \t\n\r':
|
|
return 'ppm'
|
|
|
|
tests.append(test_ppm)
|
|
|
|
def test_rast(h, f):
|
|
"""Sun raster file"""
|
|
if h.startswith(b'\x59\xA6\x6A\x95'):
|
|
return 'rast'
|
|
|
|
tests.append(test_rast)
|
|
|
|
def test_xbm(h, f):
|
|
"""X bitmap (X10 or X11)"""
|
|
if h.startswith(b'#define '):
|
|
return 'xbm'
|
|
|
|
tests.append(test_xbm)
|
|
|
|
def test_bmp(h, f):
|
|
if h.startswith(b'BM'):
|
|
return 'bmp'
|
|
|
|
tests.append(test_bmp)
|
|
|
|
def test_webp(h, f):
|
|
if h.startswith(b'RIFF') and h[8:12] == b'WEBP':
|
|
return 'webp'
|
|
|
|
tests.append(test_webp)
|
|
|
|
#--------------------#
|
|
# Small test program #
|
|
#--------------------#
|
|
|
|
def test():
|
|
import sys
|
|
recursive = 0
|
|
if sys.argv[1:] and sys.argv[1] == '-r':
|
|
del sys.argv[1:2]
|
|
recursive = 1
|
|
try:
|
|
if sys.argv[1:]:
|
|
testall(sys.argv[1:], recursive, 1)
|
|
else:
|
|
testall(['.'], recursive, 1)
|
|
except KeyboardInterrupt:
|
|
sys.stderr.write('\n[Interrupted]\n')
|
|
sys.exit(1)
|
|
|
|
def testall(list, recursive, toplevel):
|
|
import sys
|
|
import os
|
|
for filename in list:
|
|
if os.path.isdir(filename):
|
|
print(filename + '/:', end=' ')
|
|
if recursive or toplevel:
|
|
print('recursing down:')
|
|
import glob
|
|
names = glob.glob(os.path.join(filename, '*'))
|
|
testall(names, recursive, 0)
|
|
else:
|
|
print('*** directory (use -r) ***')
|
|
else:
|
|
print(filename + ':', end=' ')
|
|
sys.stdout.flush()
|
|
try:
|
|
print(what(filename))
|
|
except OSError:
|
|
print('*** not found ***')
|
|
|
|
if __name__ == '__main__':
|
|
test()
|