Example 1: Output random String
head -c 65536 /dev/urandom | tr -dc a-zA-Z0-9 | cut -c -16
Example 2: Delete all .jpg files
find . | grep .jpg$ | xargs -I@ rm @
Extra 1: Python
python3 -c "import math;print(math.pi)"
Extra 2: C++
cat<<EOF>a.cpp
#include <bits/stdc++.h>
int main() {
printf("C++ Test\n");
}
EOF
g++ a.cpp
./a.out
echo 1
echo "SHELLGEI ONLINE JUDGE"
echo 2
echo -e "SHELLGEI\nONLINE\nJUDGE"
echo 3
echo $SHELL
cat 1
cat input.txt
cat 2
cat -n input.txt
cat 3
cat -e input.txt
cat 4
cat input.txt /ShellGeiData/vol.65/input
sed 1
cat input.txt | sed 's/XXX/SHELLGEI/'
sed 2
cat input.txt | sed 's/XXX/SHELLGEI/;s/YYY/ONLINE/'
sed 3
cat input.txt | sed 's/[0-9]//g'
sed 4
cat input.txt | sed '/[0-9]/d'
sed 5
cat input.txt | sed -n '/[0-9]/p'
sed 6
cat input.txt | sed 's/\([a-z]*[0-9]\)/\1.jpg/'
find 1
find "/ShellGeiData/sd201701"
find 2
find "/ShellGeiData/sd201701" -type f
find 3
find "/ShellGeiData/sd201701" -type f -name "dangerous*"
grep 1
cat input.txt | grep ".jpg"
grep 2
cat input.txt | grep -e ".jpg" -e ".png"
grep 3
cat input.txt | grep -v ".txt"
grep 4
cat input.txt | grep ".jpg$"
awk 1
echo | awk '{print "SHELLGEI ONLINE JUDGE"}'
awk 2
cat input.txt | awk '{print $2}'
awk 3
cat input.txt | awk '{print $1,$3,$2}'
awk 4
cat input.txt | awk 'BEGIN{cnt=0}{cnt+=1}END{print cnt}'
NULL
NULL
NULL
NULL
NULL
NULL
NULL