file system
ls //list directory content
pwd //print working directory
cp //copy files
rm //remove directory entries
mkdir //make directories
ln //link files
mv // move files
touch //change file access and modification times
//-t ccyymmddhhmm.SS
cat //concatenate and print files
file //determine file type
process
ps //report process status
pstree //show running process as a tree
kill //send a signal to running process to terminate it
pkill //send signals to processes
killall //kill process according to its name
time //time a simple command or give resource usage
top //detect the sysytem status
fg // brings a process to the foreground
bg //sends a process to the background
crontab //Schedule periodic background work
search
find //find files
grep //search text for a parttern
whereis //locate some special files
相关链接：
Linux Top指令
Linux中crontab-定时任务命令
Linux的五个查找命令：find,locate,whereis,which,type
touch命令
List of Unix commands
