[Bug-wget] wget does not explicitly close the session when exiting

[Yoriyuki Yamagata]

Dear list,

I noticed that wget does not explicitly close the session when exiting.  
Looking dtruss output on Mac OS X, 

73072/0x11a24f:  read(0x6, "hts reserved.</div>\n\t\t<div 
class=\"ac-gf-footer-legal-links\"> <a class=\"ac-gf-footer-legal-link\" 
href=\"/privacy/privacy-policy/\">Privacy Policy</a> <a 
class=\"ac-gf-footer-legal-link\" 
href=\"/legal/internet-services/terms/site.html\">Terms of Use</a> <a class=", 
0x307)               = 775 0
73072/0x11a24f:  write_nocancel(0x7, "hts reserved.</div>\n\t\t<div 
class=\"ac-gf-footer-legal-links\"> <a class=\"ac-gf-footer-legal-link\" 
href=\"/privacy/privacy-policy/\">Privacy Policy</a> <a 
class=\"ac-gf-footer-legal-link\" 
href=\"/legal/internet-services/terms/site.html\">Terms of Use</a> <a class=", 
0x307)             = 775 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, " \0", 0x1)                 = 1 0
73072/0x11a24f:  write_nocancel(0x2, "100%\0", 0x4)              = 4 0
73072/0x11a24f:  write_nocancel(0x2, " 1.34M\0", 0x6)            = 6 0
73072/0x11a24f:  write_nocancel(0x2, "=0.02s\0", 0x6)            = 6 0
73072/0x11a24f:  write_nocancel(0x2, "\n\n\0", 0x2)              = 2 0
73072/0x11a24f:  close_nocancel(0x7)             = 0 0
73072/0x11a24f:  write_nocancel(0x2, "2015-12-10 15:50:34 (1.34 MB/s) - 
'index.html.1' saved [29486/29486]\n\n\0", 0x46)                 = 70 0
73072/0x11a24f:  close(0x3)              = 0 0, 

0x6 is not closed.  I double check this by inserting debug output to fd_close 
function.  It also show that fd_close is not called for 0x6.

This would not matter much, because exit() closes all fd anyways.  Probably 
this is intentional.  But, it could be regarded a bad style (ok, it depends on 
your taste).

My crude monitor says that file descriptors 4 and 5 also are not explicitly 
closed when exiting. I’m not sure its accuracy.

I am curious about your opinion.

Best,

— 
Yoriyuki Yamagata
National Institute of Advanced Science and Technology (AIST), Senior Researcher
http://staff.aist.go.jp/yoriyuki.yamagata/en/