---
name: "aediff"
section: "1"
platform: "linux"
package: "aegis"
version: "4.24.3-3"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/aediff"
---

# aediff(1)

file differences between deltas

## NAME

aediff - file differences between deltas

## SYNOPSIS

**aediff** \[ *option*... \] *filename*\
 **aediff** **-Help**\
 **aediff** **-VERSion**

## DESCRIPTION

The *aediff* command is used to obtain the difference between versions of the given *filename* across different file versions, a specified by the command lien options.

If two changes or deltas are specified, the difference between the versions of the file in each will be output.

If only one change or delta is specified, the second version defaults to the current change.

If no changes or deltas are specified, the first version defaults to the baseline and the second version defaults to the current change.

### Examples

To see the difference in the project configuration file, *aegis.conf*, between deltas 1.2.D003 and 4.5.D067 the following command may be used:

aediff aegis.conf -c 1.2.D003 -c 4.5.D067

To see the differences in the project configuration file, between the head of the 7.6 branch and the current change, the following command may be used:

aediff -branch 7.6 -bl  aegis.conf

Many, many other combinatiosn are possible.

### Using Graphical Tools

It is possible to use a graphical diff tool with the [*aediff*(1)](/aediff/1.md) command.  This is done by using the -command *option, or setting* *the* `AE2DIFF` *environment variable.  For example, to use the* *[tkdiff(1)](/tkdiff/1.md) command to display the differences you would use a* *command such as:*

*aediff --command=tkdiff filename*

*If you use this option, many of the [diff(1)](/diff/1.md)-specific options will* *be ignored.*

## OPTIONS

*The following options are understood:*

- **-BaseLine**

  *This option may be used to specify that* *the project baseline is the subject of the command.*

- **-Change** *number*

  *This option may be used to specify a particular change within a project.* *See [aegis(1)](/aegis/1.md) for a complete description of this option.*

- **-COMmand** *string*

  *This option may be used to set the command used to display differences.* *Using this option will cause [diff(1)](/diff/1.md)-specific options to be* *ignored.  If not set, defaults to the value of the* `AE2DIFF` *environment variable, or "diff" otherwise.*

- **-CONtext** *\[ lines \]*

  *Use the context output format, showing lines (an integer) lines of* *context, or three if lines is not given.  For proper operation,* *[patch(1)](/patch/1.md) typically needs at least two lines of context.*

- **-DELta** *number*

  *This option may be used to specify a particular* *delta in the project's history to copy the file from,* *rather than the most current version.* *If the delta has been given a name* *(see* [*aedn*(1)](/aedn/1.md) *for how)* *you may use a delta name instead of a delta number.* *It is an error if the delta specified does not exist.* *Delta numbers start from 1 and increase;* *delta 0 is a special case meaning “when the branch started”.*

- **-DELta\_Date** *string*

  *This option may be used to specify a particular date and time in the* *project's history to copy the file from, rather than the most current* *version.  It is an error if the string specified cannot be interpreted* *as a valid date and time.  Quote the string if you need to use spaces.*

- **-DELta\_From\_Change** *number*

  *This option may be used to specify a particular project delta from its* *change number.*

- **-Ignore\_Blank\_Lines**

  *Ignore changes that just insert or delete blank lines.*

- **-Ignore\_All\_Space**

  *Ignore white space when comparing lines.*

- **-Ignore\_Case**

  *Ignore changes in case; consider upper- and lower-case to be the same.*

- **-Ignore\_Space\_Change**

  *Ignore changes in amount of white space.*

- **-Project** *name*

  *This option may be used to select the project of interest.* *When no* **-Project** *option is specified,* *the* *AEGIS\_PROJECT* *environment variable is consulted.* *If that does not exist,* *the user's* *$HOME/.aegisrc* *file is examined for a default project field (see* [*aeuconf*(5)](/aeuconf/5.md) *for more information).* *If that does not exist,* *when the user is only working on changes within a single project,* *the project name defaults to that project.* *Otherwise,* *it is an error.*

- **-Show\_C\_Function**

  *Show which C function each change is in.*

- **-TRunk**

  *This option may be used to specify* *the project trunk for the origin file,* *rather than the baseline.* *(See also* **-BRanch** *option,* *the -trunk option is the same as the “-branch -” option.)*

- **-unified** *\[ lines \]*

  *Use the unified output format, showing lines (an integer) lines* *of context, or three if lines is not given.  For proper operation,* *[patch(1)](/patch/1.md) typically needs at least two lines of context.*

- **-Help**

  *This option may be used to obtain more information about how to use the* *aediff* *program.*

*See also* [*aediff*(1)](/aediff/1.md) *for options common to all aediff commands.*

*All options may be abbreviated;* *the abbreviation is documented as the upper case letters,* *all lower case letters and underscores (\_) are optional.* *You must use consecutive sequences of optional letters.*

*All options are case insensitive,* *you may type them in upper case or lower case or a combination of both,* *case is not important.*

*For example:* *the arguments "-project, "-PROJ" and "-p" are* *all interpreted to mean the* **-Project** *option.* *The argument "-prj" will not be understood,* *because consecutive optional characters were not supplied.*

*Options and other command line arguments may be* *mixed arbitrarily on the command line,* *after the function selectors.*\

*The GNU long option names are understood.* *Since all option names for* *aediff* *are long,* *this means ignoring the extra leading '-'.* *The "***--***option***=***value*" convention is also understood.

## EXIT STATUS

The *aediff* command will exit with a status of 1 on any error. The *aediff* command will only exit with a status of 0 if there are no errors.

## ENVIRONMENT VARIABLES

See [*aegis*(1)](/aegis/1.md) for a list of environment variables which may affect this command. See [*aepconf*(5)](/aepconf/5.md) for the project configuration file's *project\_specific* field for how to set environment variables for all commands executed by Aegis.\

## COPYRIGHT

aediff version 4.24.3.D001\
 Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Peter Miller

The aediff program comes with ABSOLUTELY NO WARRANTY; for details use the '*aediff -VERSion License*' command. This is free software and you are welcome to redistribute it under certain conditions; for details use the '*aediff -VERSion License*' command.\

## AUTHOR

| | | |
| --- | --- | --- |
| Peter Miller | E-Mail: | millerp@canb.auug.org.au |
| `/\/\*` | WWW: | http://www.canb.auug.org.au/~millerp/ |