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MAKE(1) BSD General Commands Manual MAKE(1) NAME make -- maintain program dependencies SYNOPSIS make [-BPSXeiknqrstv] [-D variable] [-d flags] [-E variable] [-f makefile] [-I directory] [-j max_jobs] [-m directory] [-V variable] [variable=value] [target ...] DESCRIPTION The make utility is a program designed to simplify the maintenance of other programs. Its input is a list of specifications describing depen- dency relationships between the generation of files and programs. The first of `makefile' and `Makefile' that can be found in either the cur- rent directory or a special object directory (see `.OBJDIR') will be read for this list of specifications. If the file `.depend' can be found, it is also read (see mkdep(1)). This manual page is intended as a reference document only. For a more thorough introduction to make and makefiles, please refer to Make - A Tutorial. The options are as follows: -B Try to be backwards compatible by executing a single shell per command and by executing the commands to make the sources of a dependency line in sequence. This is turned on by default unless -j is used. -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. Argument flags is one or more of the following: 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. f Print debugging information about the execution of for loops. Currently a no-op. 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. l Print commands in Makefiles regardless of whether or not they are prefixed by @ or other "quiet" flags. Also known as "loud" behavior. 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 variable Specify a variable whose environment value (if any) will override macro assignments within makefiles. -e Specify that environment values override macro assignments within makefiles for all variables. -f makefile Specify a makefile to read instead of the default `makefile' and `Makefile'. If makefile is `-', standard input is read. Multi- ple makefiles may be specified, and are read in the order speci- fied. -I directory Specify a directory in which to search for makefiles and included makefiles. The system makefile directory (or directories, see the -m option) is automatically included 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. Turns compatibility mode off, unless the B flag is also specified. -k Continue processing after errors are encountered, but only on those targets that do not depend on the target whose creation caused the error. -m directory Specify a directory in which to search for sys.mk and makefiles included via the <...> style. Multiple directories can be added to form a search path. This path will override the default sys- tem include path: /usr/share/mk. Furthermore, the system include path will be appended to the search path used for "..."-style in- clusions (see the -I option). -n Display the commands that would have been executed, but do not actually execute them. -P Collate the output of a given job and display it only when the job finishes, instead of mixing the output of parallel jobs to- gether. This option has no effect unless -j is used too. -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 Stop processing when an error is encountered. Default behaviour. This is needed to negate the -k option during recursive builds. -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. -V variable Print make's idea of the value of variable, in the global con- text. Do not build any targets. Multiple instances of this op- tion may be specified; the variables will be printed one per line, with a blank line for each null or undefined variable. -v Be extra verbose. For multi-job makes, this will cause file ban- ners to be generated. -X When using the -V option to print the values of variables, do not recursively expand the values. 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 expressions `?', `*', `[]' and `{}'. The expressions `?', `*' and `[]' may only be used as part of the final component of the target or source, and must be used to describe existing files. The expression `{}' 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 whitespace 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; also known as `!'. .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; also known as `%'. .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 per- mitted for backward compatibility and are not recommended. The six variables `@F', `@D', `_F', `_D', `*F', and `*D' are permit- ted 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 internal variables or environment variables: $ A single dollar sign `$', i.e. `$$' expands to a single dollar sign. MAKE The name that make was executed with (argv[0]). .CURDIR A path to the directory where make was executed. The make utility sets .CURDIR to the canonical path given by getcwd(3). .OBJDIR A path to the directory where the targets are built. At startup, make searches for an alternate directory to place target files. It will attempt to change into this special di- rectory and will search this directory for makefiles not found in the current directory. The following directories are tried in order: 1. ${MAKEOBJDIRPREFIX}/`pwd` 2. ${MAKEOBJDIR} 3. obj.${MACHINE} 4. obj 5. /usr/obj/`pwd` The first directory that make successfully changes into is used. If either MAKEOBJDIRPREFIX or MAKEOBJDIR is set in the environment but make is unable to change into the correspond- ing directory, then the current directory is used without checking the remainder of the list. If they are undefined and make is unable to change into any of the remaining three di- rectories, then the current directory is used. .MAKEFLAGS The environment variable MAKEFLAGS may contain anything that may be specified on make's command line. Its contents are stored in make's .MAKEFLAGS variable. Anything specified on make's command line is appended to the .MAKEFLAGS variable which is then entered into the environment as MAKEFLAGS for all programs which make executes. MFLAGS A synonym for .MAKEFLAGS provided for backward compatibility. PWD Alternate path to the current directory. Supported if built with WANT_ENV_PWD defined. make normally sets `.CURDIR' to the canonical path given by getcwd(3). However, if the envi- ronment variable PWD is set and gives a path to the current directory, then make sets `.CURDIR' to the value of PWD in- stead. PWD is always set to the value of `.OBJDIR' for all programs which make executes. .TARGETS List of targets make is currently building. .INCLUDES See .INCLUDES special target. .LIBS See .LIBS special target. MACHINE Name of the machine architecture make is running on, obtained from the MACHINE environment variable, or through uname(3) if not defined. MACHINE_ARCH Name of the machine architecture make was compiled for, de- fined at compilation time. VPATH Makefiles may assign a colon-delimited list of directories to VPATH. These directories will be searched for source files by make after make has finished parsing all input makefiles. Variable expansion may be modified to select or modify each word of the variable (where a "word" is whitespace-delimited sequence of characters). The general format of a variable expansion is as follows: {variable[:modifier[:...]]} Each modifier begins with a colon and one of the following special char- acters. The colon may be escaped with a backslash (`\'). C/pattern/replacement/[1g] The C modifier is just like the S modifier except that the old and new strings, instead of being simple strings, are an extended regular expression (see re_format(7)) and an ed(1)-style replacement string. Normally, the first occur- rence of the pattern in each word of the value is changed. The `1' modifier causes the substitution to apply to at most one word; the `g' modifier causes the substitution to apply to as many instances of the search pattern as occur in the word or words it is found in. Note that `1' and `g' are or- thogonal; the former specifies whether multiple words are po- tentially affected, the latter whether multiple substitutions can potentially occur within each affected word. E Replaces each word in the variable with its suffix. H Replaces each word in the variable with everything but the last component. L Converts variable to lower-case letters. Mpattern Select only those words that match the rest of the modifier. The standard shell wildcard characters (`*', `?', and `[]') may be used. The wildcard characters 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. Q Quotes every shell meta-character in the variable, so that it can be passed safely through recursive invocations of make. R Replaces each word in the variable with everything but its suffix. S/old_string/new_string/[g] Modify the first occurrence of old_string in each word of the variable's value, replacing it with new_string. If a `g' is appended to the last slash of the pattern, all occurrences in each word are replaced. If old_string begins with a caret (`^'), old_string is anchored at the beginning of each word. If old_string ends with a dollar sign (`$'), it is anchored at the end of each word. Inside new_string, an ampersand (`&') is replaced by old_string. Any character may be used as a delimiter for the parts of the modifier string. The an- choring, ampersand, and delimiter characters may be escaped with a backslash (`\'). Variable expansion occurs in the normal fashion inside both old_string and new_string with the single exception that a backslash is used to prevent the expansion of a dollar sign (`$'), not a preceding dollar sign as is usual. T Replaces each word in the variable with its last component. old_string=new_string This is the AT&T System V UNIX style variable substitution. 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. Oth- erwise % is the substring of old_string to be replaced in new_string U Converts variable to upper-case letters. DIRECTIVES, CONDITIONALS, AND FOR LOOPS Directives, conditionals, 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. The following direc- tives are supported: .include _file_ .include "file" Include the specified makefile. Variables between the angle brackets or double quotes are expanded to form the file name. If angle brackets are used, the included makefile is expected to be in the system makefile directory. If double quotes are used, the including makefile's directory and any directories specified us- ing the -I option are searched before the system makefile direc- tory. .undef variable Un-define the specified global variable. Only global variables may be un-defined. .error message Terminate processing of the makefile immediately. The filename of the makefile, the line on which the error was encountered and the specified message are printed to standard output and make terminates with exit code 1. Variables in the message are ex- panded. Conditionals are used to determine which parts of the Makefile to process. They are used similarly to the conditionals supported by the C pre-processor. The following conditionals are supported: .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 && Logical AND; of higher precedence than `||'. As in C, make will only evaluate a conditional as far as is necessary to determine its value. Parentheses 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 `&&'. 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 empty 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. An expression may also be an arithmetic or string comparison. Variable expansion is performed on both sides of the comparison, after which the integral 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 expressions, and it en- counters a word it doesn't recognize, either the "make" or "defined" ex- pression is applied to it, depending on the form of the conditional. If the form is `.ifdef' or `.ifndef', the "defined" expression is applied. 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 iter- ation 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. .WAIT If special .WAIT source is appears in a dependency line, the sources that precede it are made before the sources that suc- ceed it in the line. Loops are not being detected and tar- gets that form loops will be silently ignored. 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 only 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. .INCLUDES A list of suffixes that indicate files that can be included in a source file. The suffix must have already been declared with .SUFFIXES; any suffix so declared will have the directo- ries on its search path (see .PATH) placed in the .INCLUDES special variable, each preceded by a -I flag. .INTERRUPT If make is interrupted, the commands for this target will be executed. .LIBS This does for libraries what .INCLUDES does for include files, except that the flag used is -L. .MAIN If no target is specified when make is invoked, this target will be built. This is always set, either explicitly, or im- plicitly when make selects the default target, to give the user a way to refer to the default target on the command line. .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. .NOTPARALLEL Disable parallel mode. .NO_PARALLEL Same as above, for compatibility with other pmake variants. .ORDER The named targets are made in sequence. .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. Where possible, use of .PATH is preferred over use of the VPATH variable. .PATHsuffix The sources are directories which are to be searched for suf- fixed files not found in the current directory. The make utility first searches the suffixed search path, before re- verting to the default path if the file is not found there. This form is required for .LIBS and .INCLUDES to work. .PHONY Apply the .PHONY attribute to any specified sources. Targets with this attribute are always considered to be out of date. .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. COMPATIBILITY Older versions of make used MAKE instead of MAKEFLAGS. This was removed for POSIX compatibility. The internal variable MAKE is set to the same value as .MAKE; support for this may be removed in the future. Most of the more esoteric features of make should probably be avoided for greater compatibility. ENVIRONMENT The make utility uses the following environment variables, if they exist: MACHINE, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, and PWD. FILES .depend list of dependencies Makefile list of dependencies makefile list of dependencies obj object directory sys.mk system makefile (processed before any other file, including makefile and Makefile) /usr/share/mk system makefile directory /usr/share/doc/psd/12.make PMake tutorial /usr/obj default MAKEOBJDIRPREFIX directory. BUGS The determination of .OBJDIR is contorted to the point of absurdity. In the presence of several .MAIN special targets, make silently ignores all but the first. .TARGETS is not set to the default target when make is invoked without a target name and no .MAIN special target exists. The evaluation of expression in a test is very simple-minded. Currently, the only form that works is `.if ${VAR} op something' For instance, you should write tests as `.if ${VAR} = string' not the other way around, which doesn't work. For loops are expanded before tests, so a fragment such as: .for TMACHINE in ${SHARED_ARCHS} .if ${TMACHINE} = ${MACHINE} ... .endif .endfor won't work, and should be rewritten the other way around. SEE ALSO mkdep(1), make.conf(5) PMake - A Tutorial. in /usr/share/doc/psd/12.make HISTORY A make command appeared in Version 7 AT&T UNIX. BSD March 19, 1994 BSD
NAME | SYNOPSIS | DESCRIPTION | FILE DEPENDENCY SPECIFICATIONS | SHELL COMMANDS | VARIABLE ASSIGNMENTS | DIRECTIVES, CONDITIONALS, AND FOR LOOPS | COMMENTS | SPECIAL SOURCES | SPECIAL TARGETS | COMPATIBILITY | ENVIRONMENT | FILES | BUGS | SEE ALSO | HISTORY
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