How to Change the Default Font on Windows 7 (with Pictures)Select a font. Doing so will apply it to your selected item (e. Title Bar) in the preview window near the top of the page. If you don't like your selected font, try a different one. You can also change the font's formatting (e. To bold or italicize your font, click B or I respectively. They're right of the font name and size. Environment variable - Wikipedia. An environment variable is a dynamic- namedvalue that can affect the way running processes will behave on a computer. They are part of the environment in which a process runs. For example, a running process can query the value of the TEMP environment variable to discover a suitable location to store temporary files, or the HOME or USERPROFILE variable to find the directory structure owned by the user running the process. They were introduced in their modern form in 1. Version 7 Unix, so are included in all Unixoperating system flavors and variants from that point onward including Linux and mac. OS. From PC DOS 2. Mass Convert File Names in Windows with a Batch File [How To] All that's required is the name of the files to be moved, and the name of the file it is to be moved to. An environment variable is a dynamic-named value that can affect the way running processes will behave on a computer. They are part of the environment in which a. 14 Back-to-School Apps That Will Keep Your School Burden Light Your backup plan: Best backup apps for Windows and Mac Microsoft Office and top. Notepad is a very lightweight text editor for Windows with very few options. If you're looking for more powerful alternatives, here are some to check out. Microsoft operating systems including Microsoft Windows, and OS/2 also have included them as a feature, although with somewhat different syntax, usage and standard variable names. In all Unix and Unix- like systems, each process has its own separate set of environment variables. By default, when a process is created, it inherits a duplicate environment of its parent process, except for explicit changes made by the parent when it creates the child. At the API level, these changes must be done between running fork and exec. Alternatively, from command shells such as bash, a user can change environment variables for a particular command invocation by indirectly invoking it via env or using the ENVIRONMENT_VARIABLE=VALUE < command> notation. A running program can access the values of environment variables for configuration purposes. Shell scripts and batch files use environment variables to communicate data and preferences to child processes. They can also be used to store temporary values for reference later in a shell script. However, in Unix, other variables are usually used for this. In Unix, an environment variable that is changed in a script or compiled program will only affect that process and possibly child processes. The parent process and any unrelated processes will not be affected. In MS- DOS, changing or removing a variable's value inside a batch file will change the variable for the duration of COMMAND. COM's existence. In Unix, the environment variables are normally initialized during system startup by the system init scripts, and hence inherited by all other processes in the system. Users can, and often do, augment them in the profile script for the command shell they are using. In Microsoft Windows, each environment variable's default value is stored in the Windows registry or set in the AUTOEXEC. BAT file. On Unix, a setuid program is given an environment chosen by its caller, but it runs with different authority from its caller. The dynamic linker will usually load code from locations specified by the environment variables $LD_LIBRARY_PATH and $LD_PRELOAD and run it with the process's authority. If a setuid program did this, it would be insecure, because its caller could get it to run arbitrary code and hence misuse its authority. For this reason, libc unsets these environment variables at startup in a setuid process. The variables can be used both in scripts and on the command line. They are usually referenced by putting special symbols in front of or around the variable name. For instance, to display the user home directory, in most scripting environments, the user has to type: In DOS, OS/2 and Windows command- line interpreters such as COMMAND. COM and cmd. exe, the user has to type this: In Windows Power. Shell, the user has to type this: Write- Output$env: HOMEPATHThe commands env, set, and printenv display all environment variables and their values. Assignment[edit]The commands env and set are also used to set environment variables and are often incorporated directly into the shell. In Unix, the following commands can also be used, but are often dependent on a certain shell. VARIABLE=value #. VARIABLE # for Bourne and related shells. VARIABLE=value # for ksh, bash, and related shells. VARIABLEvalue # for csh and related shells. A few simple principles govern how environment variables achieve their effect. Environment variables are local to the process in which they were set. If two shell processes are spawned and the value of an environment variable is changed in one, that change will not be seen by the other. When a child process is created, it inherits all the environment variables and their values from the parent process. Usually, when a program calls another program, it first creates a child process by forking, then the child adjusts the environment as needed and lastly the child replaces itself with the program to be called. This procedure gives the calling program control over the environment of the called program. In Unix and Unix- like systems, the names of environment variables are case- sensitive. In Unix shells, variables may be assigned without the export keyword. Variables defined in this way are displayed by the set command, but are not true environment variables, as they are stored only by the shell and not recognized by the kernel. The printenv command will not display them, and child processes do not inherit them. VARIABLE=value. However, if used in front of a program to run, the variables will be exported to the environment and thus appear as real environment variables to the program: VARIABLE=value program_name [arguments]. The persistence of an environment variable can be session- wide or system- wide. Bourne shell family (sh, ksh, bash, etc.) and the C shell family (csh, tcsh, etc.) of Unix command line shells. It unsets a shell variable, removing it from memory and the shell's exported environment. It is implemented as a shell builtin, because it directly manipulates the internals of the shell.[1][2]Read- only shell variables cannot be unset. If one tries to unset a read- only variable, the unset command will print an error message and return a non- zero exit code. DOS, OS/2 and Windows[edit]In DOS, OS/2 and Windows command- line interpreters such as COMMAND. COM and cmd. exe, the SET command is used to assign environment variables and values using the following arguments. SET VARIABLE=value. The SET command without any arguments displays all environment variables along with their values. Examples[edit]Examples of environment variables include: PATH: a list of directory paths. When the user types a command without providing the full path, this list is checked to see whether it contains a path that leads to the command. HOME (Unix- like) and USERPROFILE (Microsoft Windows): indicate where a user's home directory is located in the file system. HOME/{. App. Name} (Unix- like) and APPDATA\{Developer. Name\App. Name} (Microsoft Windows): for storing application settings. Many applications incorrectly use USERPROFILE for application settings in Windows: USERPROFILE should only be used in dialogs that allow user to choose between paths like Documents/Pictures/Downloads/Music; for programmatic purposes, APPDATA (for roaming application settings shared across multiple devices), LOCALAPPDATA (for local application settings) or PROGRAMDATA (for application settings shared between multiple OS users) should be used.[3]TERM (Unix- like): specifies the type of computer terminal or terminal emulator being used (e. PS1 (Unix- like): specifies how the prompt is displayed in the Bourne shell and variants. MAIL (Unix- like): used to indicate where a user's mail is to be found. TEMP: location where processes can store temporary files. True environment variables[edit]$PATHContains a colon- separated list of directories that the shell searches for commands that do not contain a slash in their name (commands with slashes are interpreted as file names to execute, and the shell attempts to execute the files directly). It is equivalent to the DOS, OS/2 and Windows%PATH% variable.$HOMEContains the location of the user's home directory. Although the current user's home directory can also be found out through the C- functions getpwuid and getuid, $HOME is often used for convenience in various shell scripts (and other contexts). Using the environment variable also gives the user the possibility to point to another directory.$PWDThis variable points to the current directory. Equivalent to the output of the command pwd when called without arguments.$DISPLAYContains the identifier for the display that X1.
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