ps
report a snapshot of the current processes
curl
transfer data from or to a server, using one of the supported protocols (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP)
top
display system summary information as well as a list of processes or threads currently being managed by the Linux kernel
grep
ex) grep 'PATTERNS' FILE
searches for PATTERNS in each FILE. PATTERNS is one or more patterns separated by newline characters, and grep prints each line that matches a pattern. Typically PATTERNS should be quoted when grep is used in a shell command.
tail
Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name.
find
search for files in a directory hierarchy
chmod
change file mode bits
&
ex) command1 & command2
앞의 명령어를 백그라운드로 돌리고 동시에 뒤의 명령어를 실행
&&
ex) command1 && command2
앞문장의 결과가 참이면 뒷문장도 실행함