| I classified the linux commands basic which used for regular use and tool specific commands | |||
| in linux all are files even hardware and directory | |||
| description | command | USED option instead of complete list | |
| change the shell | chsh | ||
| list the command history of shell | fc | l | |
| recently used commands | history | ||
| disk free information | df | k | |
| size of current folder ( disk usage ) | du -hs | ||
| to know who are else logged into system | finger | ||
| short version of a command | info | ||
| Display detail help content of a command | man | -k | |
| used to display the large file | More & less | it is do scroll bar task of windows | |
| display first or last given no. Of lines of file | Head & tail | ||
| display content of file | cat | ||
| display content type of a file | file | ||
| basename | |||
| small editor | nano | ||
| basic editor | vi | ||
| Xmanager – tool for connect unix | |||
| change the password | passwd | vmc server install in linux , and use client in window machine. | |
| add one directory in a variable ( usully PATH ) | export | ||
| desktop calucator | dc | ||
| more complex float or double artimetic operation | bc | ||
| expression evaluation | expr | ||
| present working directory | pwd | ||
| cd | |||
| ls | |||
| copy file | cp | ||
| mv | |||
| rm | |||
| echo | n | ||
| display all the command who are aliased | alias | ||
| sort | |||
| uniq | |||
| spell | |||
| search a given file in computer ( it check all dir/subdirecory ) | find | ||
| quick search in system database for given file ( check only PATH value ) | locate | ||
| search a line in file for given pattern | grep | -n,-v,-c,-i | |
| extended grep | egrep | ||
| to list name of installed package, it is debian specific | dpkg -l | RedHad and suse are mostly used in industries | |
| to list name of groups in system | groups | it just a mechanism to manage the users | |
| used to edit etc/crontab file, | crontab | ||
| it is daemon thread, check periodically etc/crontab file | cron | ||
| to check the file system. | fsck | ||
| to know path of a command (that is existence of command in os ) | which | which ls/cd/mv/etc. | |
| to know all path of a command | whereis | ||
| It is mainly used for abbreviating a system command, or for adding default arguments to a regularly used command | alias | ||
| to list name of process | ps | e, f, a, u, x | |
| display the process in tree structure | pstree | ||
| display top 5 proecess | top | ||
| show virutual memory statuss | vmstat | ||
| to know the command information | apropos | ||
| to know how long a given command executed | time <cmd> | ||
| to lanuch another command | exec | ||
| config network devices | ifconfig | ||
| to reflect configuration file changes to current session without logout | source | ||
| shell sleep for given seconds | sleep | ||
| to terminate shell script execution | exit | ||
| make is command to create binary file ( like ant ) | make | ||
| always return true used in shell scripting (Built in command in shell itself . No binary file for this command) | 1 | ||
| always return true used in shell scripting (Built in command in shell itself . No binary file for this command) | 0 | ||
| Built in command in shell itself for test numeric, string and file comparision . No binary file for this command in system. | test | ||
| it used to identity shell built in commands like true, false, test, [, etc. type itself built in command | type | ex: type test, type true | |
| tr | |||
| octal dump | od | a | |
| diplay only GLOBAL the environment variable | env | ||
| diplay only GLOBAL the environment variable | printenv | ||
| diplay all LOCAL as well as ENVIRONMENT (exported ) the environment variable | set | ||
| just remove a variable name itself. | unset | ||
| cut | |||
| used to find/replace/search on a given file and create new file from output | sed | e | |
| another popular stream editor like sed | awk/gawk | ||
| another popular stream editor like sed | perl | ||
| to send message to all user who logged into system | wall | ||
| to send message to a particular user | write | ||
| archieve utility | tar | ||
| compress and expand utility | zcat | ||
| data dumper | dd | ||
| display the OS name, processor, mother board architecure, etc, | uname | o, hardware-platform, p,a, all | |
| administrative command | who | ||
| who are all logged in, administrative command | w | ||
| display the current user | whoami | ||
| make many file to single file | tar | c, f | |
| compress while creating archieve file | compress | ||
| uncompress while extracting archieve file | uncompress | ||
| it is best compare with compress command. It take a tar file to compress | gzip | ||
| it is lates of gzip | bzip2 | ||
| to un compress a compressed file by gzip | gunzip | ||
| it has both create and compress the archieve file. It useful to if file used in window os | zip | ||
| test command's alternative | [ | ||
| truncate the file | >or : > | ||
| continuation for command line | \ | ||
| input rediirect from a file | < | ||
| redirect output and append if a file alreay | >> | ||
| redirect output and truncate if file already | > | ||
| recirect output of a command to ANOTHER COMMAND | |||
| to run a command in background mode | & | ||
| current process id | $$ | ||
| recent background process id | $! | ||
| recent command's exit status | $? |