Receiver Socked File Descriptor
Question Text
What is the type of the file descriptor that corresponds to the socket created by support/send-receive/receiver.py?
Question Answers
-
only file descriptors that are linked to files have types
-
DIR -
REG -
CHR -
IPv4
Feedback
Running lsof yields the following output:
student@os:~$ lsof -p 59681
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
python3 59681 student cwd DIR 8,1 0 559322 /home/student/operating-systems-oer/content/chapters/io/lab/support/send-receive
python3 59681 student rtd DIR 259,6 4096 2 /
python3 59681 student txt REG 259,6 5502744 1835857 /usr/bin/python3.8
python3 59681 student mem REG 259,6 8631488 1835827 /usr/lib/locale/locale-archive
python3 59681 student mem REG 259,6 108936 1835887 /usr/lib/x86_64-linux-gnu/libz.so.1.2.11
python3 59681 student mem REG 259,6 182560 1836149 /usr/lib/x86_64-linux-gnu/libexpat.so.1.6.11
python3 59681 student mem REG 259,6 1369384 1857443 /usr/lib/x86_64-linux-gnu/libm-2.31.so
python3 59681 student mem REG 259,6 14880 1857476 /usr/lib/x86_64-linux-gnu/libutil-2.31.so
python3 59681 student mem REG 259,6 18848 1857439 /usr/lib/x86_64-linux-gnu/libdl-2.31.so
python3 59681 student mem REG 259,6 157224 1857471 /usr/lib/x86_64-linux-gnu/libpthread-2.31.so
python3 59681 student mem REG 259,6 2029592 1857435 /usr/lib/x86_64-linux-gnu/libc-2.31.so
python3 59681 student mem REG 259,6 27002 2506848 /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache
python3 59681 student mem REG 259,6 191504 1835092 /usr/lib/x86_64-linux-gnu/ld-2.31.so
python3 59681 student 0u CHR 136,1 0t0 4 /dev/pts/1
python3 59681 student 1u CHR 136,1 0t0 4 /dev/pts/1
python3 59681 student 2u CHR 136,1 0t0 4 /dev/pts/1
python3 59681 student 3u IPv4 588386 0t0 UDP localhost:5000
The last line displays the socket:
python3 59681 student 3u IPv4 588386 0t0 UDP localhost:5000
Its type is written on the the 5th column: IPv4 because it’s a network socket.