Command Magic

command.magic.sh

# Find out the connections of a process
lsof -i -a -p <PID>

# Find out the route table
netstat -nr
netstat -A inet -p | grep <pattern of process>

# Find out the ip of a domain name
nslookup <domain name>

# Change the default route to local under VPN
sudo route change default <local gateway>

# Add route for specific ips
sudo route -nv add -net <ip range> -interface <Netif>

# Trace a route path to a address
traceroute <address>

# Dump HTTP GET with content
tcpdump -X -i eth0 '(port 9091) and (tcp[(tcp[12]>>2):4] = 0x47455420)' -w dump.txt

# Turn off and Turn on the Wifi
networksetup -setairportpower airport off; sleep 10; networksetup -setairportpower airport on

# Search one level depth with hidden files
ag --depth 1 -u JAVA_HOME .

# Proxy remote port to local via ssh connnection
ssh -f -NTML <local_port>:<remote_domain>:<remote_port> <ssh_user>@<ssh_domain>

cut.examples.sh

# Examples for (GNU) cut


# ==== -b, --bytes=LIST ====
echo hello | gcut -b 2
#> e

echo hello | gcut -b -2
#> he

echo hello | gcut -b 2,5
#> eo

echo hello | gcut -b 1,3-5
#> hllo


# ==== -c, --characters=LIST ====
echo 你好 | gcut -c 1
#> � ;; Not working for GNU cut

echo 你好 | cut -c 1
#> 你 ;; Works fine for BSD cut


# ==== -d, --delimiter ====
echo hello | gcut -dl -f1
#> he

echo hello | gcut -dl -f2
#> ⏎

echo hello | gcut -dl -f3
#> o

echo hello | gcut -dl -f1,3
#> helo ;; Using `l` as the output delimiter


# ==== --complement ====
echo hello | gcut -b2 --complement
#> hllo


# ==== -s, --only-delimited ====
echo hello | gcut -da -f1
#> hello

echo hello | gcut -da -f1 -s
#> ⏎


# ==== --output-delimiter ====
echo hello | gcut -dl -f1,3 --output-delimiter -
#> he-o


# ==== -z, --zero-terminated ====
echo -e "hello\0hello" | gcut -de -f2
#> lloh


echo echo -e "hello\0hello" | gcut -de -f2 -z
#> llollo ;; See the stdin as two lines

gxargs.examples.sh

# Examples for (GNU) xargs


# ==== -0, --null ====
echo -e "hello\0world" | gxargs -n1
#> gxargs: WARNING: a NUL character occurred in the input.  It cannot be passed through in the argument list.  Did you mean to use the --null option?
#> hello

echo -e "hello\0world" | gxargs --null -n1
#> hello
#> world
#> ⏎

# ==== -a file, --arg-file=file ====
echo -e "hello\nworld" > /tmp/xargs; gxargs --arg-file=/tmp/xargs -n1
#> hello
#> world

# ==== --delimiter=delim, -d delim ====
echo -e "hello\nworld" | gxargs --delimiter=o -n1
#> hell
#> ⏎
#> w
#> rld
#> ⏎

# ==== -E eof-str ====
echo -e "hello\nworld" | gxargs -E world -n1
#> hello

# ==== -e[eof-str], --eof[=eof-str] ====
# Not recommended, use -E instead

# ==== -I replace-str ====
echo -e "hello\nworld" | gxargs -I x -n1 echo x=x
#> hello=hello
#> world=world

# ==== -i[replace-str], --replace[=replace-str] ====
echo -e "hello\nworld" | gxargs -i -n1 echo "{}={}"
#> hello=hello
#> world=world

# ==== -L max-lines ====
echo -e "he\nllo\nwor\nld" | gxargs -L2
#> he llo
#> wor ld

# ==== -l[max-lines], --max-lines[=max-lines] ====
echo -e "hello\nworld" | gxargs
#> hello world

echo -e "hello\nworld" | gxargs -l
#> hello
#> world

# ==== -n max-args, --max-args=max-args ====
echo -e "hello\nworld" | gxargs -l2 -n1
#> hello
#> world

echo -e "hello\nworld" | gxargs -n1 -l2
#> hello world

# ==== -P max-procs, --max-procs=max-procs ====
echo -e "hello\nworld" | gxargs -i -n1 -P 2 sh -c "sleep 1;echo {}"
#> world
#> hello

# ==== -p, --interactive ====
echo -e "hello\nworld" | gxargs -l -p
#> echo hello ?...y
#> hello
#> echo world ?...y
#> world

# ==== --process-slot-var=name ====
echo -e "hello\nworld" | gxargs -n1 --process-slot-var=NUM -P2 sh -c 'echo [$NUM] $@' x
#> [0] hello
#> [1] world

# ==== -r, --no-run-if-empty ====
echo -e "" | gxargs
#> ⏎

echo -e "" | gxargs -r
#> 🚫

# ==== -s max-chars, --max-chars=max-chars ====
echo -e "hello\nworld" | gxargs -l -s10
#> gxargs: argument line too long

echo -e "hello\nworld" | gxargs -l -s11
#> hello
#> world

# ==== --show-limits ====
echo -e "hello\nworld" | gxargs -l -s11 --show-limits
#> Your environment variables take up 1516 bytes
#> POSIX upper limit on argument length (this system): 258580
#> POSIX smallest allowable upper limit on argument length (all systems): 4096
#> Maximum length of command we could actually use: 257064
#> Size of command buffer we are actually using: 11
#> Maximum parallelism (--max-procs must be no greater): 2147483647
#> hello
#> world

# ==== -t, --verbose ====
echo -e "hello\nworld" | gxargs -l -t
#> echo hello
#> hello
#> echo world
#> world

# ==== -x, --exit ====
echo $status
#> 0
echo -e "hello\nworld" | gxargs -n2 -s15
#> hello
#> world
echo $status
#> 0

echo $status
#> 0
echo -e "hello\nworld" | gxargs -n2 -s15 -x
#> gxargs: argument list too long
echo $status
#> 1