More UNIX Utilities for Shell programming

1. More UNIX Utilities for Shell programming

2. at-at, batch--execute commands at a later time

3. awk--pattern scanning and processing language

4. banner--make posters

5. basename--with a directory name delivers portions of the pathname

6. bc--processes precision arithmetic

7. bdiff—compares two big files • bdiff compares two files that are too large for diff.

8. cal—displays a calendar

9. cat—concatenates and displays files

10. chmod—change the permissions mode of a file

11. chown—changes owner of a file

12. clear, clears the terminal screen

13. cmp—compares two files

14. compress—compress, uncompress, zcat compress, uncompress files, or display expanded files

15. cp — copies files

16. cpio —copy file archives in and out

17. cron—the clock daemon • cron executes commands at specified dates and times. Regularly scheduled jobs can be specified in the /etc/crontab file. (Must have superuser privileges)

18. crypt—encode or decode a file • cryptencrypts and decrypts the contents of a file. The password is a key that selects a type of transformation

19. cut—removes selected fields or characters from each line of a file

20. date—displays the date and time or sets the date

21. diff—compares two files for differences diff [-biw][-c] | -Cn

22. du—summarizes disk usage

23. echo—echoes arguments

24. egrep—searches a file for a pattern using full regular expressions

25. expr—evaluates arguments as an expression

26. fgrep—search a file for a character string

27. file—determines the type of a file by looking at its contents

28. find—finds files

29. finger—displays information about local and remote users • By default, the finger command displays information about each logged in user, including login name, full name, terminal line (prepended with a ‘*’ if write permission is denied), idle time, login time, and location if known

30. fmt—simple text formatters

31. fold—folds long lines • Fold the contents of the specified filenames, or the standard input if no files are specified, breaking the lines to have maximum width. The default for width is 80. Width should be a multiple of 8 if tabs are present, or the tabs should be expanded

32. ftp—file transfer program

33. getop(s)—parses command line options • The getopts command supersede getop. getops is used to break up options in command lines for easy parsing by shell procedures and to check for legal options.

34. grep—searches a file or a program

35. groups—prints group membership of user • The command groups prints on standard output the groups to which you or the optionally specified user belong.

36. id—prints the username, user ID, group name and group ID • iddisplays your user ID,user name, group ID, and group name. If your real ID and your effective ID’s do not match, both are printed.

37. jsh—the standard, job control shell • The command jsh in an interface to the standard Bourne shell which provides all of the functionality of the Bourne shell and enables job control.

38. line—reads one line • line copies one line (up to a new line) from the standard input and writes it on the standard output. It returns an exit code of one on EOF and always prints at least a new line. It is often used within shell files to read from the user’s terminal.

39. logname—gets the name of the user running the process

40. lp(ATT)—sends output to a printer

41. lpr(UCB)—sends output to a printer

42. lpsat(ATT)—print information about the status of the LP print service

43. lpq(UCB)—print information about the status of the printer

44. ls —lists a contents of directory

45. mail—mail, rmail—read mail or send mail to users • A recipient is usually a username recognized by login. When recipients are named, mail assumes a message is being sent. It reads from the standard input up to an end-of-file(Ctrl-D), or if reading from a terminal, until it reads a line consisting of just a period. When either of those indicators is received, mail adds the letter to the mailfile for each recipient.

46. mailx—interactive message processing system • The mail utilities listed above provide an interactive interface for sending, receiving, and manipulating mail messages. Basic networking utilities must be installed for some of the features to work. Incoming mail is stored in a file called mailbox, and after it is read, it sends to a file called mbox

47. make—maintains, updates, and regenerates groups of related program and files • make updates file according to commands listed in a description file, and if the target file is newer than the dependency file of the same name, make will update the target file.

48. mesg—permits or denies messages resulting from the write command • mesg without argument –n forbids messages via write by revoking no user write permission on the user’s terminal. mesg with argument –y reinstates permission. All by itself, mesg reports the current state without changing it.

49. mkdir—creates a directory

50. more—browse or page through a text file • more is a filter that displays the contents of a text file on the terminal, one screenful at a time. It normally pauses after each screenful, and prints “—More—” at the bottom of the screen.