[List]
❑
list="A1 B1 C1 D1"
❑
AAA=$(echo {101..105} → AAA="101 102
[For]
❑ for ele1 in $list
do
echo "This is" $ele1
done
do
echo "This is" $ele1
done
❑
for num1 in {100..105}
do
done
do
done
[While]
❑
while [ : ]
do
done
do
done
[Case]
❑
case $var1 in
1) echo 1 ;;
2) echo 2 ;;
3) echo 3 ;;
4) echo 4 ;;
esac
1) echo 1 ;;
2) echo 2 ;;
3) echo 3 ;;
4) echo 4 ;;
esac
[If]
❑
if [ $var1 == "n" ]
then
echo "n"
else
echo "not n"
fi
then
echo "n"
else
echo "not n"
fi
❑
if [ -e ./test.txt ] : True if the "./test.txt" is exists, false if not.
❑
if [ $? -eq 0 ] : True if exit status is 0.
❑
if [ $PERCENT -ge "30" ] : $PERCENT >= 30
| Arithmetic operator | Description |
| val1 –eq val2 | True if the val1 and the val2 is equal. |
| val1 –ne val2 | True if the val1 and the val2 is not equal. |
| val1 –gt val2 | >. True if the val1 is greater than the val2. |
| val1 –lt val2 | <. True if the val1 is less than the val2. |
| val1 –ge val2 | >=. True if the val1 is equal or greater than the val2. |
| val1 – le val2 | <=. True if the val1 is equal or less than the val2. |
| String operator | Description |
| -z val1 | True if the val1's length is 0. |
| -n val1 | True if the val1's length is not 0. |
| va1 = val2 val1 == val2 | True if the val1 is equal to val2. |
| val1 != val2 | True if the val1 is not equal to val2. |
| val1 | True if the val1 is not null string. |
| Logical operator | Description |
| val1 -a val2 | AND operator. |
| val1 -o val2 | OR operator. |
| File operator | Description |
| -b file1 | True if the file1 is a block device file. |
| -c file1 | True if the file1 is a character device file. |
| -d file1 | True if the file1 is a directory file. |
| -S file1 | True if the file1 is a socket file. |
| -t file1 | True if the file1 is a opened terminal file. |
| -e file1 | True if the file1 is exist. |
| -s file1 | Ture if the file1's size is greater than 0. |
| -f file1 | True if the file1 is a regular file. |
| -O file1 | True if the file1's owned user is current user. |
| -G file1 | True if the file1's owned group is current group. |
| -u file1 | True if the file1 has the SetUID permission. |
| -g file1 | True if the file1 has the SetGID permission. |
| -k file1 | True if the file1 has the Sticky bit permission. |
| -h file1 -L file1 | True if the file1 is a symbolic link file. |
| -p file1 | True if the file1 is a named pipe file. |
| -r file1 | True if the file1 has the read permission. |
| -w file1 | True if the file1 has the write permission. |
| -x file1 | True if the file1 has the execute permission. |
| file1 -nt file2 | True if the file1 is newer than the file2. |
| file1 -ot file2 | True if the file1 is older than the file2. |
| file1 -ef file2 | True if the file1 is equal(Hard link) to the file2. |
[Misc]
❑
echo $(date '+%y')"year "$(date '+%m')"month "$(date '+%d')"day "$(date '+%H')":"$(date '+%M')":"$(date '+%S') → 18year 06month 04day 01:02:10
❑
echo $(date '+%y%m%d%H%M%S') → 180604010210
❑
${fileName%*.exe} : Remove ".exe" at the end of the fileName.
❑
$1 : The first argument of the program.
❑
$2 : The second argument of the program.
❑
read var1
❑
read -p "Enter Your Username?[user] → The user's input data will be stored in the variable var1.
* p : Option to receive user's input in one line including guide.
❑
echo "1+2" | bc → 3
❑
echo "scale=3;10/3" | bc → 3.333
* bc(Basic Calculator) : Perform the arithmetic operations.