Parameters and Variables 321 in .NET Draw EAN-13 Supplement 2 in .NET Parameters and Variables 321

Parameters and Variables 321 using vs .net toreceive ean13+2 in web,windows application QR Code Features $ PATH=/usr/local/bin:$PATH:~/bin MAIL: Where Your Mail Is Kept The MAIL var UPC-13 for .NET iable contains the pathname of the file that holds your mail (your mailbox, usually /var/mail/name, where name is your username). If MAIL is set and MAILPATH (next) is not set, the shell informs you when mail arrives in the file specified by MAIL.

In a graphical environment you can unset MAIL so the shell does not display mail reminders in a terminal emulator window (assuming you are using a graphical mail program). The MAILPATH variable contains a list of filenames separated by colons. If this variable is set, the shell informs you when any one of the files is modified (for example, when mail arrives).

You can follow any of the filenames in the list with a question mark ( ), followed by a message. The message replaces the you have mail message when you receive mail while you are logged in. The MAILCHECK variable specifies how often, in seconds, the shell checks for new mail.

The default is 60 seconds. If you set this variable to zero, the shell checks before each prompt..

PS1: User Prompt (Primary). The default EAN 13 for .NET Bourne Again Shell prompt is a dollar sign ($). When you run bash with root privileges, bash typically displays a hashmark (#) prompt.

The PS1 variable holds the prompt string that the shell uses to let you know that it is waiting for a command. When you change the value of PS1, you change the appearance of your prompt. You can customize the prompt displayed by PS1.

For example, the assignment. $ PS1="[\u@\h \W \!]$ ". displays the UPC-13 for .NET following prompt: [user@host directory event]$ where user is the username, host is the hostname up to the first period, directory is the basename of the working directory, and event is the event number (page 331) of the current command. If you are working on more than one system, it can be helpful to incorporate the system name into your prompt.

For example, you might change the prompt to the name of the system you are using, followed by a colon and a SPACE (a SPACE at the end of the prompt makes the commands you enter after the prompt easier to read). This command uses command substitution (page 362) in the string assigned to PS1:. $ PS1="$(hos tname): " echo test test bravo. 322 9 The Bourne Again Shell The first ex ample that follows changes the prompt to the name of the local host, a SPACE, and a dollar sign (or, if the user is running with root privileges, a hashmark). The second example changes the prompt to the time followed by the name of the user. The third example changes the prompt to the one used in this book (a hashmark for root and a dollar sign otherwise):.

$ PS1="\h \$ " bravo $ $ PS1="\@ \u $ " 09:44 PM max $ $ PS1="\$ " $ Table 9-4 de scribes some of the symbols you can use in PS1. For a complete list of special characters you can use in the prompt strings, open the bash man page and search for the second occurrence of PROMPTING (give the command /PROMPTING and then press n)..

Table 9-4. Symbol \$ \w \W \! \d \h \H \u \@ \T \A \t PS1 symbols Display in prompt # if the use EAN13 for .NET r is running with root privileges; otherwise, $ Pathname of the working directory Basename of the working directory Current event (history) number (page 335) Date in Weekday Month Date format Machine hostname, without the domain Full machine hostname, including the domain Username of the current user Current time of day in 12-hour, AM/PM format Current time of day in 12-hour HH:MM:SS format Current time of day in 24-hour HH:MM format Current time of day in 24-hour HH:MM:SS format. PS2: User Prompt (Secondary). The PS2 vari visual .net UPC-13 able holds the secondary prompt. On the first line of the next example, an unclosed quoted string follows echo.

The shell assumes the command is not finished and, on the second line, gives the default secondary prompt (>). This prompt indicates the shell is waiting for the user to continue the command line. The shell waits until it receives the quotation mark that closes the string.

Only then does it execute the command:.
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