mirror of
https://github.com/python/cpython.git
synced 2024-12-22 08:14:22 +08:00
0b95290f4e
svn+ssh://pythondev@svn.python.org/python/trunk ........ r65713 | benjamin.peterson | 2008-08-16 11:29:02 -0500 (Sat, 16 Aug 2008) | 1 line #3424 rearrange the order of tests in imghdr to place more common types first ........
157 lines
3.4 KiB
Python
157 lines
3.4 KiB
Python
"""Recognize image file formats based on their first few bytes."""
|
|
|
|
__all__ = ["what"]
|
|
|
|
#-------------------------#
|
|
# Recognize image headers #
|
|
#-------------------------#
|
|
|
|
def what(file, h=None):
|
|
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)
|
|
f = None
|
|
else:
|
|
f = None
|
|
try:
|
|
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)
|
|
|
|
#--------------------#
|
|
# 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 IOError:
|
|
print('*** not found ***')
|
|
|
|
if __name__ == '__main__':
|
|
test()
|