Linux常用命令

Linux常用命令

du -m |sed 's/\-/\ /' |awk '{printf "%+12s   %-10s\n",$1,$2}' |sort -n

du -m |tr '-' ' ' |awk '{printf "%+12s   %-10s\n",$1,$2}' |sort -n

for循环

for i in 1 2 3; do echo "$i ---"; done

for i in `ls *.txt`; do echo $(ls -l $i);done

total=0; for (( i=1; i<=10; i++)); do total=$(( $total + $i )); done; echo $total; 

while循环

i=1; while(($i < 10)); do i=$(($i + 1)); echo $i; done

i=1; while(($i<10)); do i=$(($i+1)); echo $i; done  //表达式中间也可以没有空格

i=1; while(($i < 10)); do i=$(($i + 1)); echo $i; done

i=1 
while(($i<10)) 
do 
  i=$(($i+1)) 
  if(($i%2==0)) 
    then 
    echo "--2x: $i"
  fi
done 

计算器

awk 'BEGIN{a=3;b=5;print "a+b="a+b; print "b/2="b/a }'
expr 1 + 2
expr 1 \* 2
echo $((3/2))

awk & xargs

ls -1 |awk '{print "ls -l "$1}'
ls -1 |xargs -I {} echo ls -l {}
find *.rpm |xargs -I {} chmod u+x {}

expr

# expr length "abc" 
3
# expr 3 / 2
1
# expr 3 \* 2
6
# expr substr "hello test" 1 2
he
# expr index "hello test" h
1
# expr index "hello test" e
2 
# expr index "hello test" l
3 
# expr index "hello test" hello
1 
# expr index "hello test" test
2
# i=5; expr $i + 1

6