Capture Nethogs Output in Log File

Capture nethogs output in log file

You can use this command to capture output:

nethogs -d 5 | sed 's/[^[:print:][:cntrl:]]//g' > output.txt

redirecting console output to a file in unix

Possibly the large amount of output is "permission denied" type messages. Redirect errors to the log file by appending 2>&1.

2 is the stream number for stderr (error messages), 1 is represents the stdout stream (the standard non-error output stream).

find . -iname "MyLog.log" > ./myfile/storeLog.log 2>&1

redirecting console output to a file in unix

Possibly the large amount of output is "permission denied" type messages. Redirect errors to the log file by appending 2>&1.

2 is the stream number for stderr (error messages), 1 is represents the stdout stream (the standard non-error output stream).

find . -iname "MyLog.log" > ./myfile/storeLog.log 2>&1

ifstat logging bandwidth usage

awk is buffering its output. Normally, most programs use line buffering when stdout is a terminal but switch to larger buffer sizes when stdout is not a terminal, and awk is no exception. If you ran your command for long enough, you'd eventually see the file size grow in chunks of size 4096 or so (possibly more or less) as the buffer fills up and gets flushed.

To force awk to flush its buffer after every line regardless of whether or not stdout is a terminal, add an fflush() command:

/usr/bin/ifstat -i eth0 -b -n | awk 'NR>2 {print "Download" $1 "upload" $2; fflush()}' > bandwidth.txt

Programmatic resource monitoring per process in Linux

/usr/src/linux/Documentation/accounting/taskstats.txt

Taskstats is a netlink-based interface for sending per-task and
per-process statistics from the kernel to userspace.

Taskstats was designed for the following benefits:

• efficiently provide statistics during lifetime of a task and on its exit
• unified interface for multiple accounting subsystems
• extensibility for use by future accounting patches

This interface lets you monitor CPU, memory, and I/O usage by processes of your choosing. You only need to set up and receive messages on a single socket.

This does not differentiate (for example) disk I/O versus network I/O. If that's important to you, you might go with a LD_PRELOAD interception library that tracks socket operations. Assuming that you can control the startup of the programs you wish to observe and that they won't do trickery behind your back, of course.

I can't think of any light-weight solutions if those still fail, but linux-audit can globally trace syscalls, which seems a fair bit more direct than re-capturing and analyzing your own network traffic.

PHP network monitoring debian

The info you need is in /proc/net/dev

# cat /proc/net/dev
Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
    lo:  177937    1304    0    0    0     0          0         0   177937    1304    0    0    0     0       0          0
  eth0:16268834   14619    0    0    0 10091          0         0  1201136   10555   20    0    0     0       0          0

For the transfer rate you will have to calculate the delta from the previous capture but the value will be approximate.

How to get process or port Network bandwidth usage in linux

As far as I know Linux doesn't offer an alternative interface to pcap for calculating network usage. /proc/<PID>/stat(us) contains various process information but nothing about network access, only the total I/O usage including disk access.

Similarly, to know the port you have to read at least the IP header. Hence I assume it is not possible to speed this up significantly, because analyzing all packets in user space will always be slow. A kernel module for this task seems to be the only option.

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