1. File Systems
| Command | Usage |
| cd | change working directory |
| chgrp | change the group of a file or library |
| chmod | change the access permission of a file |
| chown | change the owner of a file or library |
| cp | copy files or directories |
| dd | use to block input/output operations on files and performing conversions on them |
| df | ("disk free") reports available space and space in use in drives accessible by your system |
| du | report the amount of disk space used by a hierarchy of directories |
| find | search for files or directories that match a certain criterion, i.e. name, modification time etc |
| ln | make a hard link or symbolic link |
| ls | list contents of directory |
| mkdir | create a new directory |
| mv | rename files or move them to other directory |
| pwd | print name of working directory |
| rm | remove files or directories |
| rmdir | remove directories |
| touch | create a new empty file or update the modification time of an existing file |
| wget | a non-interactive network retriever |
| which | show the full path of commands, functions, header files |
2. Binary Files
| Command | Usage |
| ar | archive maintenance utility; create libraries to be linked to other programs |
| nm | list the symbol in an executable, object file or libary |
| ranlib | generate an index for an ar format archive; enables faster linking |
| size | print the sizes of sections in object files and executable programs |
| strings | print the ASCII text strings embedded in binary file |
| strip | remove debugging symbols and line number information from files to make file smaller |
| wget | Download files using http or ftp URL |
| curl | Download files using http or ftp URL |
| hexdump | Dump files in hexadecimal numbers and ASCII characters |
| Command | Usage |
| awk | scan one or more files and perform an action on all of the lines that match a particular conditon |
| cat | concatenate files together and send the result to the standard output |
| cksum | calculate a CRC checksum for files |
| csplit | context based file splitter |
| cut | cut out selected fields of each line of a file |
| egrep | search a file for a pattern using full regular expressions |
| expand | replace the tabs in a file with a specified number of spaces |
| fgrep | searched a file for fixed-character string |
| fmt | simple text formatters |
| fold | wrap files to fit in a specified number of columns |
| grep | include also grep,egrep and fgrep; search for patterns matching on lines in a file |
| head | print a specified number of lines from the beginning of a file |
| indent | formatter for C source code |
| join | conditionally merge two files together based on matching fields in the files |
| less | a display paginator similar to more and pg in UNIX |
| make | update a file based on a series of dependency rules stored in a special format |
| md5sum | calculate a "fingerprint" for files using the MD5 algorithm |
| more | copy by the screenful |
| nl | add line number to files |
| od | dump the contents of a file in a number format, including octal,hex and several ASCII format |
| patch | apply changes to files |
| paste | merge multiple files together into one file by concatenating lines from each file to form one line in the output file |
| pr | pring files |
| sed | "stream editor" based on the line editor ed; useful for editing streams of data |
| sort | sort lines in a file based on fields in the file |
| split | cut files into multiple fixed size pieces |
| sum | calculate a simple checksum for files |
| tail | print a specified number of line from the end of a file |
| tr | character translation |
| tsort | topological sort |
| troff | typeset or format documents | |
| unexpand | "unexpand" sequences of a specified number of spaces into tab characters |
| uniq | remove duplicate lines from a sorted file |
| vi | screen text editor |
| vim | improved vi with syntax highlighting for Ch |
| wc | count characters, words and/or lines in a file |
5. Shell Utilities
| Command | Usage |
| basename | echo its argument, a file name, minus any directory name |
| date | display date and time of the system |
| dirname | print the directory component of file name |
| echo | print its argument\\ |
| env | used to modify the environment in which a program is run |
| expr | evaluate various types of expressions involving arithmetic,relational,logical and string operators |
| factor | get all prime factors for a positive integer |
| hostname | the name of the local host machine |
| id | display the user and group IDs and names |
| logname | display the user's login name |
| pathchk | check path names |
| printenv | ouput the environment under which a command will execute |
| sh | the Bourne shell |
| sleep | stop all actions in a shell for a specified period of time |
| tee | copy its standard input to files named on the command line and also to standard output |
| uname | display information about computer system; set node name (system name) |
| whoami | display the login name |
| xargs | construct argument lists and invoke utility |