[LINUX] Shell memo

Shell

if statement

IF[ $０-eq 0]
THEN
echo "success"
ELIF[ $０-eq 1]
THEN
echo "failed,code is 1"
FI

for statement

#FOREACH
for i in $@
do
	echo $i
done

#FOR
for((i =0; i <10; i++))
do
	echo $i
done

while statement

while["$ans"!="yes"]
do
read -p "please input yes to exit loop:" ans
done

head | tail

#Get the contents before the Nth line from the top
head +20 notes.log
#Get the contents before the Nth line from the bottom
head -20 notes.log

#Surveillance
tail -f notes.log
#Get the contents after the Nth line from the top
tail +20 notes.log
#Get the contents after the Nth line from the bottom
tail -20 notes.log

grep

#Get the line containing the character you want to search
grep "string" *.txt
#Get the line that does not contain the character you want to search
grep -V "string" *.txt
#Use regular expressions
grep -E "string[0-9]" *.txt
#Other use cases
cat file | grep "string"

find

#Search files and folders commands
#Search files and folders by name
find path -name "*.txt"
find path -name "*.txt" -type f #Search only files
find path -name "*.txt" -type d #Search only folders
#Search by permission specification
find path -perm 777
#Search by user
find path -user root
#Search by change time
find path -mtime -5 #Things within 5 days
find path -mtime +3 #3 days or older
#Search by size
find path -size +1024ｋ #1M or more
find path -size -1024ｋ #1M or less
#Add other processing to what you searched for
find path -name "*.txt"|xargs rm -rf #Delete
find path -name "*.txt"|xargs ls -l #View permissions

sed

#Display the second line ($Is the last line)
sed -n '2'p file
#Display the 1st to 4th lines
sed -n '1,4'p file
#Use regular expression, show lines containing los
sed -n '/los/'p file
#Use regular expression, display the contents from the 4th line to the line including los
sed -n '4,/los/'p file
#Do not display the first and second lines
sed -n '1,2'd file

awk

#Show all columns in file
awk '{print $0}' file.txt
#Show columns 1 and 7 in the file
awk '{print $１,$7}' file.txt
#Show columns 1 and 7 in the file(Columns separated by ":")
awk -F: '{print $１”\t”$7}' file.txt
#Convert the first column of the third row in the file to an integer and display it(NR means row, NF means column)
awk '{if(NR==3){print int($１)}}' file.txt
#In the file[192.168.100.1]Show all columns including(「!~Does not include)
cat file | awk '{print $１~/192.168.100.1/{print $0}}' 

crul

uniq

#Display with duplicate content excluded
uniq file
#Show the number of duplicates
uniq -c file
#Show only duplicate lines
uniq -d file

sort

#ascending order
sort file 
#descending order
sort -r file 
#「:Divided by ", descending order of the first row
cat file | sort -t: -k1 -r

less

Other

#Examine the process
ps -ef | grep ssh
#Statistics the number of rows
xxxx | wc -l
#Folder copy (if dir2 does not exist)
cp -r dir1 dir2
#Split the file every 5 lines
split -5 file newfile