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MAKE(1)                      BSD Reference Manual                      MAKE(1)

NAME
     make - maintain program dependencies

SYNOPSIS
     make [-eiknqrstv] [-D variable] [-d flags] [-f makefile] [-I directory]
          [-j max_jobs] [variable=value] [target ...]

DESCRIPTION
     Make is a program designed to simplify the maintenance of other programs.
     Its input is a list of specifications as to the files upon which programs
     and other files depend.  If the file `makefile' exists, it is read for
     this list of specifications.  If it does not exist, the file `Makefile'
     is read.  If the file `.depend' exists, it is read (see mkdep(1)).

     This manual page is intended as a reference document only.  For a more
     thorough description of make and makefiles, please refer to Make - A
     Tutorial.

     The options are as follows:

     -D variable
             Define variable to be 1, in the global context.

     -d flags
             Turn on debugging, and specify which portions of make are to
             print debugging information.  Flags is one or more of the follow-
             ing:

             A       Print all possible debugging information; equivalent to
                     specifying all of the debugging flags.

             a       Print debugging information about archive searching and
                     caching.

             c       Print debugging information about conditional evaluation.

             d       Print debugging information about directory searching and
                     caching.

             g1      Print the input graph before making anything.

             g2      Print the input graph after making everything, or before
                     exiting on error.

             j       Print debugging information about running multiple
                     shells.

             m       Print debugging information about making targets, includ-
                     ing modification dates.

             s       Print debugging information about suffix-transformation
                     rules.

             t       Print debugging information about target list mainte-
                     nance.

             v       Print debugging information about variable assignment.

     -e      Specify that environmental variables override macro assignments
             within makefiles.

     -f makefile
             Specify a makefile to read instead of the default `makefile' and
             `Makefile'. If makefile is `-', standard input is read.  Multiple
             makefile's may be specified, and are read in the order specified.

     -I directory
             Specify a directory in which to search for makefiles and included
             makefiles.  The system makefile directory is automatically in-
             cluded as part of this list.

     -i      Ignore non-zero exit of shell commands in the makefile.  Equiva-
             lent to specifying `-' before each command line in the makefile.

     -j max_jobs
             Specify the maximum number of jobs that make may have running at
             any one time.

     -k      Continue processing after errors are encountered, but only on
             those targets that do not depend on the target whose creation
             caused the error.

     -n      Display the commands that would have been executed, but do not
             actually execute them.

     -q      Do not execute any commands, but exit 0 if the specified targets
             are up-to-date and 1, otherwise.

     -r      Do not use the built-in rules specified in the system makefile.

     -s      Do not echo any commands as they are executed.  Equivalent to
             specifying `@' before each command line in the makefile.

     -t      Rather than re-building a target as specified in the makefile,
             create it or update its modification time to make it appear up-
             to-date.

     variable=value
             Set the value of the variable variable to value.

     There are seven different types of lines in a makefile: file dependency
     specifications, shell commands, variable assignments, include statements,
     conditional directives, for loops, and comments.

     In general, lines may be continued from one line to the next by ending
     them with a backslash (`\'). The trailing newline character and initial
     whitespace on the following line are compressed into a single space.

FILE DEPENDENCY SPECIFICATIONS
     Dependency lines consist of one or more targets, an operator, and zero or
     more sources.  This creates a relationship where the targets ``depend''
     on the sources and are usually created from them.  The exact relationship
     between the target and the source is determined by the operator that sep-
     arates them.  The three operators are as follows:

     :     A target is considered out-of-date if its modification time is less
           than those of any of its sources.  Sources for a target accumulate
           over dependency lines when this operator is used.  The target is
           removed if make is interrupted.

     !     Targets are always re-created, but not until all sources have been
           examined and re-created as necessary.  Sources for a target accumu-
           late over dependency lines when this operator is used.  The target
           is removed if make is interrupted.

     ::    If no sources are specified, the target is always re-created.  Oth-
           erwise, a target is considered out-of-date if any of its sources
           has been modified more recently than the target.  Sources for a
           target do not accumulate over dependency lines when this operator
           is used.  The target will not be removed if make is interrupted.

     Targets and sources may contain the shell wildcard values `?', `*', `[]'
     and `{}'. The values `?', `*' and `[]' may only be used as part of the
     final component of the target or source, and must be used to describe ex-
     isting files.  The value `{}' need not necessarily be used to describe
     existing files.  Expansion is in directory order, not alphabetically as
     done in the shell.

SHELL COMMANDS
     Each target may have associated with it a series of shell commands, nor-
     mally used to create the target.  Each of the commands in this script
     must be preceded by a tab.  While any target may appear on a dependency
     line, only one of these dependencies may be followed by a creation
     script, unless the `::' operator is used.

     If the first or first two characters of the command line are `@' and/or
     `-', the command is treated specially.  A `@' causes the command not to
     be echoed before it is executed.  A `-' causes any non-zero exit status
     of the command line to be ignored.

VARIABLE ASSIGNMENTS
     Variables in make are much like variables in the shell, and, by tradi-
     tion, consist of all upper-case letters.  The five operators that can be
     used to assign values to variables are as follows:

     =       Assign the value to the variable.  Any previous value is overrid-
             den.

     +=      Append the value to the current value of the variable.

     ?=      Assign the value to the variable if it is not already defined.

     :=      Assign with expansion, i.e. expand the value before assigning it
             to the variable.  Normally, expansion is not done until the vari-
             able is referenced.

     !=      Expand the value and pass it to the shell for execution and as-
             sign the result to the variable.  Any newlines in the result are
             replaced with spaces.

     Any white-space before the assigned value is removed; if the value is be-
     ing appended, a single space is inserted between the previous contents of
     the variable and the appended value.

     Variables are expanded by surrounding the variable name with either curly
     braces (`{}') or parentheses (`()') and preceding it with a dollar sign
     (`$'). If the variable name contains only a single letter, the surround-
     ing braces or parentheses are not required.  This shorter form is not
     recommended.

     Variable substitution occurs at two distinct times, depending on where
     the variable is being used.  Variables in dependency lines are expanded
     as the line is read.  Variables in shell commands are expanded when the
     shell command is executed.

     The four different classes of variables (in order of increasing prece-
     dence) are:

     Environment variables
             Variables defined as part of make's environment.

     Global variables
             Variables defined in the makefile or in included makefiles.

     Command line variables

             Variables defined as part of the command line.

     Local variables
             Variables that are defined specific to a certain target.  The
             seven local variables are as follows:

             .ALLSRC   The list of all sources for this target; also known as
                       `>'.

             .ARCHIVE  The name of the archive file.

             .IMPSRC   The name/path of the source from which the target is to
                       be transformed (the ``implied'' source); also known as
                       `<'.

             .MEMBER   The name of the archive member.

             .OODATE   The list of sources for this target that were deemed
                       out-of-date; also known as `?'.

             .PREFIX   The file prefix of the file, containing only the file
                       portion, no suffix or preceding directory components;
                       also known as `*'.

             .TARGET   The name of the target; also known as `@'.

             The shorter forms `@', `?', `>' and `*' are permitted for back-
             ward compatibility with historical makefiles and are not recom-
             mended.  The six variables `@F', `@D', `<F', `<D', `*F' and `*D'
             are permitted for compatibility with AT&T System V UNIX makefiles
             and are not recommended.

             Four of the local variables may be used in sources on dependency
             lines because they expand to the proper value for each target on
             the line.  These variables are `.TARGET', `.PREFIX', `.ARCHIVE',
             and `.MEMBER'.

             In addition, make sets or knows about the following variables:

             $          A single dollar sign `$', i.e.  `$$' expands to a sin-
                        gle dollar sign.

             .MAKE      The name that make was executed with (argv [0])

             .CURDIR    A path to the directory where make was executed.

             .OBJDIR    A path to the directory where the targets are built.

             MAKEFLAGS  The environment variable `MAKEFLAGS' may contain any-
                        thing that may be specified on make's command line.
                        Anything specified on make's command line is appended
                        to the `MAKEFLAGS' variable which is then entered into
                        the environment for all programs which make executes.

             Variable expansion may be modified to select or modify each word
             of the variable (where a ``word'' is white-space delimited se-
             quence of characters).  The general format of a variable expan-
             sion is as follows:

                   {variable[:modifier[:...]]}

             Each modifier begins with a colon and one of the following spe-
             cial characters.  The colon may be escaped with a backslash


             (`\').

             E           Replaces each word in the variable with its suffix.

             H           Replaces each word in the variable with everything
                         but the last component.

             Mpattern    Select only those words that match the rest of the
                         modifier.  The standard shell wildcard characters
                         (`*', `?', and `[]') may be used.  The wildcard char-
                         acters may be escaped with a backslash (`\').

             Npattern    This is identical to `M', but selects all words which
                         do not match the rest of the modifier.

             R           Replaces each word in the variable with everything
                         but its suffix.

             S/old_pattern/new_pattern/[g]
                         Modify the first occurrence of old_pattern in each
                         word to be replaced with new_pattern. If a `g' is ap-
                         pended to the last slash of the pattern, all occur-
                         rences in each word are replaced.  If old_pattern be-
                         gins with a carat (`^'), old_pattern is anchored at
                         the beginning of each word.  If old_pattern ends with
                         a dollar sign (`$'), it is anchored at the end of
                         each word.  Inside new_string, an ampersand (`&') is
                         replaced by old_pattern. Any character may be used as
                         a delimiter for the parts of the modifier string.
                         The anchoring, ampersand and delimiter characters may
                         be escaped with a backslash (`\').

                         Variable expansion occurs in the normal fashion in-
                         side both old_string and new_string with the single
                         exception that a backslash is used to prevent the ex-
                         pansion of a dollar sign (`$') not a preceding dollar
                         sign as is usual.

             T           Replaces each word in the variable with its last com-
                         ponent.

             old_string=new_string
                         This is the AT&T System V UNIX style variable substi-
                         tution.  It must be the last modifier specified.  If
                         old_string or new_string do not contain the pattern
                         matching character % then it is assumed that they are
                         anchored at the end of each word, so only suffixes or
                         entire words may be replaced. Otherwise % is the sub-
                         string of old_string to be replaced in new_string

INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
     Makefile inclusion, conditional structures and for loops  reminiscent of
     the C programming language are provided in make. All such structures are
     identified by a line beginning with a single dot (`.') character.  Files
     are included with either `.include <file>' or `.include "file"'. Vari-
     ables between the angle brackets or double quotes are expanded to form
     the file name.  If angle brackets are used, the included makefile is ex-
     pected to be in the system makefile directory.  If double quotes are
     used, the including makefile's directory and any directories specified
     using the -I option are searched before the system makefile directory.

     Conditional expressions are also preceded by a single dot as the first
     character of a line.  The possible conditionals are as follows:

     .undef variable
             Un-define the specified global variable.  Only global variables

             may be un-defined.

     .if [!]expression [operator expression ...]
             Test the value of an expression.

     .ifdef [!]variable [operator variable ...]
             Test the value of a variable.

     .ifndef [!]variable [operator variable ...]
             Test the value of a variable.

     .ifmake [!]target [operator target ...]
             Test the target being built.

     .ifnmake [!]target [operator target ...]
             Test the target being built.

     .else   Reverse the sense of the last conditional.

     .elif [!]expression [operator expression ...]
             A combination of `.else' followed by `.if'.

     .elifdef [!]variable [operator variable ...]
             A combination of `.else' followed by `.ifdef'.

     .elifndef [!]variable [operator variable ...]
             A combination of `.else' followed by `.ifndef'.

     .elifmake [!]target [operator target ...]
             A combination of `.else' followed by `.ifmake'.

     .elifnmake [!]target [operator target ...]
             A combination of `.else' followed by `.ifnmake'.

     .endif  End the body of the conditional.

     The operator may be any one of the following:

     ||     logical OR

     &&amp;&&amp;     Logical AND; of higher precedence than ``''.

     As in C, make will only evaluate a conditional as far as is necessary to
     determine its value.  Parenthesis may be used to change the order of
     evaluation.  The boolean operator `!' may be used to logically negate an
     entire conditional.  It is of higher precedence than `&&amp;&&amp;'.

     The value of expression may be any of the following:

     defined     Takes a variable name as an argument and evaluates to true if
                 the variable has been defined.

     make        Takes a target name as an argument and evaluates to true if
                 the target was specified as part of make's command line or
                 was declared the default target (either implicitly or explic-
                 itly, see .MAIN) before the line containing the conditional.

     empty       Takes a variable, with possible modifiers, and evaluates to
                 true if the expansion of the variable would result in an emp-
                 ty string.

     exists      Takes a file name as an argument and evaluates to true if the
                 file exists.  The file is searched for on the system search


                 path (see .PATH).

     target      Takes a target name as an argument and evaluates to true if
                 the target has been defined.

     Expression may also be an arithmetic or string comparison.  Variable ex-
     pansion is performed on both sides of the comparison, after which the in-
     tegral values are compared.  A value is interpreted as hexadecimal if it
     is preceded by 0x, otherwise it is decimal; octal numbers are not sup-
     ported.  The standard C relational operators are all supported.  If after
     variable expansion, either the left or right hand side of a `==' or `!='
     operator is not an integral value, then string comparison is performed
     between the expanded variables.  If no relational operator is given, it
     is assumed that the expanded variable is being compared against 0.

     When make is evaluating one of these conditional expression, and it en-
     counters a word it doesn't recognize, either the ``make'' or ``defined''
     expression is applied to it, depending on the form of the conditional.
     If the form is `.ifdef' or `.ifndef', the ``defined'' expression is ap-
     plied.  Similarly, if the form is `.ifmake' or `.ifnmake, the ``make'''
     expression is applied.

     If the conditional evaluates to true the parsing of the makefile contin-
     ues as before.  If it evaluates to false, the following lines are
     skipped.  In both cases this continues until a `.else' or `.endif' is
     found.

     For loops are typically used to apply a set of rules to a list of files.
     The syntax of a for loop is:

     .for variable in expression
             <make-rules>



     .endfor
     After the for expression is evaluated, it is split into words. The itera-
     tion variable is successively set to each word, and substituted in the
     make-rules inside the body of the for loop.

COMMENTS
     Comments begin with a hash (`#') character, anywhere but in a shell com-
     mand line, and continue to the end of the line.

SPECIAL SOURCES
     .IGNORE     Ignore any errors from the commands associated with this tar-
                 get, exactly as if they all were preceded by a dash (`-').

     .MAKE       Execute the commands associated with this target even if the
                 -n or -t options were specified.  Normally used to mark re-
                 cursive make's.

     .NOTMAIN    Normally make selects the first target it encounters as the
                 default target to be built if no target was specified.  This
                 source prevents this target from being selected.

     .OPTIONAL   If a target is marked with this attribute and make can't fig-
                 ure out how to create it, it will ignore this fact and assume
                 the file isn't needed or already exists.

     .PRECIOUS   When make is interrupted, it removes any partially made tar-
                 gets.  This source prevents the target from being removed.

     .SILENT     Do not echo any of the commands associated with this target,


                 exactly as if they all were preceded by an at sign (`@').

     .USE        Turn the target into make's. version of a macro.  When the
                 target is used as a source for another target, the other tar-
                 get acquires the commands, sources, and attributes (except
                 for .USE) of the source.  If the target already has commands,
                 the .USE target's commands are appended to them.

SPECIAL TARGETS
     Special targets may not be included with other targets, i.e. they must be
     the only target specified.

     .BEGIN      Any command lines attached to this target are executed before
                 anything else is done.

     .DEFAULT    This is sort of a .USE rule for any target (that was used on-
                 ly as a source) that make can't figure out any other way to
                 create.  Only the shell script is used.  The .IMPSRC variable
                 of a target that inherits .DEFAULT's commands is set to the
                 target's own name.

     .END        Any command lines attached to this target are executed after
                 everything else is done.

     .IGNORE     Mark each of the sources with the .IGNORE attribute.  If no
                 sources are specified, this is the equivalent of specifying
                 the -i option.

     .INTERRUPT  If make is interrupted, the commands for this target will be
                 executed.

     .MAIN       If no target is specified when make is invoked, this target
                 will be built.

     .MAKEFLAGS  This target provides a way to specify flags for make when the
                 makefile is used.  The flags are as if typed to the shell,
                 though the -f option will have no effect.

     .PATH       The sources are directories which are to be searched for
                 files not found in the current directory.  If no sources are
                 specified, any previously specified directories are deleted.

     .PRECIOUS   Apply the .PRECIOUS attribute to any specified sources.  If
                 no sources are specified, the .PRECIOUS attribute is applied
                 to every target in the file.

     .SILENT     Apply the .SILENT attribute to any specified sources.  If no
                 sources are specified, the .SILENT attribute is applied to
                 every command in the file.

     .SUFFIXES   Each source specifies a suffix to make. If no sources are
                 specified, any previous specified suffices are deleted.

ENVIRONMENT
     Make utilizes the following environment variables, if they exist: MAKE,
     MAKEFLAGS and MAKEOBJDIR.

FILES
     .depend        list of dependencies
     Makefile       list of dependencies
     makefile       list of dependencies
     sys.mk         system makefile
     /usr/share/mk  system makefile directory

SEE ALSO
     mkdep(1)

HISTORY
     A Make command appeared in Version 7 AT&T UNIX.

4.4BSD                          April 29, 1995                               9