Buffering issue when looking at netcat output
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I have problem I am trying to understand:
I am sending some UDP data to local host. It is a simple UDP packet with a counter. It counts up to 16 (0xF) and stops. When I grep the received data on the output, and grep only shows up to packet 11 (0xB) received. All the packets are actually received, but either grep or xxd is buffering. I have sent the data to a file to check if all is received, and the data is coming through.
[testuser %] netcat -l 127.0.0.1 -u -p 8777 | xxd -e -u | grep DEAD
00000000: 00000000 DEADBEEF FFFFFFFF DEADBEEF ................
00000400: 00000001 DEADBEEF FFFFFFFF DEADBEEF ................
00000800: 00000002 DEADBEEF FFFFFFFF DEADBEEF ................
00000c00: 00000003 DEADBEEF FFFFFFFF DEADBEEF ................
00001000: 00000004 DEADBEEF FFFFFFFF DEADBEEF ................
00001400: 00000005 DEADBEEF FFFFFFFF DEADBEEF ................
00001800: 00000006 DEADBEEF FFFFFFFF DEADBEEF ................
00001c00: 00000007 DEADBEEF FFFFFFFF DEADBEEF ................
00002000: 00000008 DEADBEEF FFFFFFFF DEADBEEF ................
00002400: 00000009 DEADBEEF FFFFFFFF DEADBEEF ................
00002800: 0000000A DEADBEEF FFFFFFFF DEADBEEF ................
00002c00: 0000000B DEADBEEF FFFFFFFF DEADBEEF ................
I suspect this is a buffering problem ... I used od (Octal dump) and I could see the full sequence, but I like the xxd output better and would like it to work.
grep pipe netcat buffer xxd
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
add a comment |
up vote
0
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I have problem I am trying to understand:
I am sending some UDP data to local host. It is a simple UDP packet with a counter. It counts up to 16 (0xF) and stops. When I grep the received data on the output, and grep only shows up to packet 11 (0xB) received. All the packets are actually received, but either grep or xxd is buffering. I have sent the data to a file to check if all is received, and the data is coming through.
[testuser %] netcat -l 127.0.0.1 -u -p 8777 | xxd -e -u | grep DEAD
00000000: 00000000 DEADBEEF FFFFFFFF DEADBEEF ................
00000400: 00000001 DEADBEEF FFFFFFFF DEADBEEF ................
00000800: 00000002 DEADBEEF FFFFFFFF DEADBEEF ................
00000c00: 00000003 DEADBEEF FFFFFFFF DEADBEEF ................
00001000: 00000004 DEADBEEF FFFFFFFF DEADBEEF ................
00001400: 00000005 DEADBEEF FFFFFFFF DEADBEEF ................
00001800: 00000006 DEADBEEF FFFFFFFF DEADBEEF ................
00001c00: 00000007 DEADBEEF FFFFFFFF DEADBEEF ................
00002000: 00000008 DEADBEEF FFFFFFFF DEADBEEF ................
00002400: 00000009 DEADBEEF FFFFFFFF DEADBEEF ................
00002800: 0000000A DEADBEEF FFFFFFFF DEADBEEF ................
00002c00: 0000000B DEADBEEF FFFFFFFF DEADBEEF ................
I suspect this is a buffering problem ... I used od (Octal dump) and I could see the full sequence, but I like the xxd output better and would like it to work.
grep pipe netcat buffer xxd
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I have problem I am trying to understand:
I am sending some UDP data to local host. It is a simple UDP packet with a counter. It counts up to 16 (0xF) and stops. When I grep the received data on the output, and grep only shows up to packet 11 (0xB) received. All the packets are actually received, but either grep or xxd is buffering. I have sent the data to a file to check if all is received, and the data is coming through.
[testuser %] netcat -l 127.0.0.1 -u -p 8777 | xxd -e -u | grep DEAD
00000000: 00000000 DEADBEEF FFFFFFFF DEADBEEF ................
00000400: 00000001 DEADBEEF FFFFFFFF DEADBEEF ................
00000800: 00000002 DEADBEEF FFFFFFFF DEADBEEF ................
00000c00: 00000003 DEADBEEF FFFFFFFF DEADBEEF ................
00001000: 00000004 DEADBEEF FFFFFFFF DEADBEEF ................
00001400: 00000005 DEADBEEF FFFFFFFF DEADBEEF ................
00001800: 00000006 DEADBEEF FFFFFFFF DEADBEEF ................
00001c00: 00000007 DEADBEEF FFFFFFFF DEADBEEF ................
00002000: 00000008 DEADBEEF FFFFFFFF DEADBEEF ................
00002400: 00000009 DEADBEEF FFFFFFFF DEADBEEF ................
00002800: 0000000A DEADBEEF FFFFFFFF DEADBEEF ................
00002c00: 0000000B DEADBEEF FFFFFFFF DEADBEEF ................
I suspect this is a buffering problem ... I used od (Octal dump) and I could see the full sequence, but I like the xxd output better and would like it to work.
grep pipe netcat buffer xxd
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
I have problem I am trying to understand:
I am sending some UDP data to local host. It is a simple UDP packet with a counter. It counts up to 16 (0xF) and stops. When I grep the received data on the output, and grep only shows up to packet 11 (0xB) received. All the packets are actually received, but either grep or xxd is buffering. I have sent the data to a file to check if all is received, and the data is coming through.
[testuser %] netcat -l 127.0.0.1 -u -p 8777 | xxd -e -u | grep DEAD
00000000: 00000000 DEADBEEF FFFFFFFF DEADBEEF ................
00000400: 00000001 DEADBEEF FFFFFFFF DEADBEEF ................
00000800: 00000002 DEADBEEF FFFFFFFF DEADBEEF ................
00000c00: 00000003 DEADBEEF FFFFFFFF DEADBEEF ................
00001000: 00000004 DEADBEEF FFFFFFFF DEADBEEF ................
00001400: 00000005 DEADBEEF FFFFFFFF DEADBEEF ................
00001800: 00000006 DEADBEEF FFFFFFFF DEADBEEF ................
00001c00: 00000007 DEADBEEF FFFFFFFF DEADBEEF ................
00002000: 00000008 DEADBEEF FFFFFFFF DEADBEEF ................
00002400: 00000009 DEADBEEF FFFFFFFF DEADBEEF ................
00002800: 0000000A DEADBEEF FFFFFFFF DEADBEEF ................
00002c00: 0000000B DEADBEEF FFFFFFFF DEADBEEF ................
I suspect this is a buffering problem ... I used od (Octal dump) and I could see the full sequence, but I like the xxd output better and would like it to work.
grep pipe netcat buffer xxd
grep pipe netcat buffer xxd
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
edited Dec 8 at 3:49
Jeff Schaller
38k1053123
38k1053123
asked Dec 8 at 3:21
Xofo
2331313
asked Dec 8 at 3:21
Xofo
2331313
asked Dec 8 at 3:21
Xofo
2331313
2331313
add a comment |
add a comment |
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