$ man make > man-docs/make.md
pi@raspberrypi:~/Desktop $ cat man-docs/make.md
MAKE(1) User Commands MAKE(1)
NAME
make - GNU make utility to maintain groups of programs
SYNOPSIS
make [OPTION]... [TARGET]...
DESCRIPTION
The make utility will determine automatically which pieces of a large program need to be recompiled, and is‐
sue the commands to recompile them. The manual describes the GNU implementation of make, which was written
by Richard Stallman and Roland McGrath, and is currently maintained by Paul Smith. Our examples show C pro‐
grams, since they are very common, but you can use make with any programming language whose compiler can be
run with a shell command. In fact, make is not limited to programs. You can use it to describe any task
where some files must be updated automatically from others whenever the others change.
To prepare to use make, you must write a file called the makefile that describes the relationships among
files in your program, and the states the commands for updating each file. In a program, typically the exe‐
cutable file is updated from object files, which are in turn made by compiling source files.
Once a suitable makefile exists, each time you change some source files, this simple shell command:
make
suffices to perform all necessary recompilations. The make program uses the makefile description and the
last-modification times of the files to decide which of the files need to be updated. For each of those
files, it issues the commands recorded in the makefile.
make executes commands in the makefile to update one or more target names, where name is typically a program.
If no -f option is present, make will look for the makefiles GNUmakefile, makefile, and Makefile, in that or‐
der.
Normally you should call your makefile either makefile or Makefile. (We recommend Makefile because it ap‐
pears prominently near the beginning of a directory listing, right near other important files such as
README.) The first name checked, GNUmakefile, is not recommended for most makefiles. You should use this
name if you have a makefile that is specific to GNU make, and will not be understood by other versions of
make. If makefile is '-', the standard input is read.
make updates a target if it depends on prerequisite files that have been modified since the target was last
modified, or if the target does not exist.
OPTIONS
-b, -m
These options are ignored for compatibility with other versions of make.
-B, --always-make
Unconditionally make all targets.
-C dir, --directory=dir
Change to directory dir before reading the makefiles or doing anything else. If multiple -C options are
specified, each is interpreted relative to the previous one: -C / -C etc is equivalent to -C /etc. This
is typically used with recursive invocations of make.
-d Print debugging information in addition to normal processing. The debugging information says which
files are being considered for remaking, which file-times are being compared and with what results,
which files actually need to be remade, which implicit rules are considered and which are applied---ev‐
erything interesting about how make decides what to do.
--debug[=FLAGS]
Print debugging information in addition to normal processing. If the FLAGS are omitted, then the behav‐
ior is the same as if -d was specified. FLAGS may be a for all debugging output (same as using -d), b
for basic debugging, v for more verbose basic debugging, i for showing implicit rules, j for details on
invocation of commands, and m for debugging while remaking makefiles. Use n to disable all previous de‐
bugging flags.
-e, --environment-overrides
Give variables taken from the environment precedence over variables from makefiles.
-f file, --file=file, --makefile=FILE
Use file as a makefile.
-i, --ignore-errors
Ignore all errors in commands executed to remake files.
-I dir, --include-dir=dir
Specifies a directory dir to search for included makefiles. If several -I options are used to specify
several directories, the directories are searched in the order specified. Unlike the arguments to other
flags of make, directories given with -I flags may come directly after the flag: -Idir is allowed, as
well as -I dir. This syntax is allowed for compatibility with the C preprocessor's -I flag.
-j [jobs], --jobs[=jobs]
Specifies the number of jobs (commands) to run simultaneously. If there is more than one -j option, the
last one is effective. If the -j option is given without an argument, make will not limit the number of
jobs that can run simultaneously. When make invokes a sub-make, all instances of make will coordinate to
run the specified number of jobs at a time; see the section PARALLEL MAKE AND THE JOBSERVER for details.
--jobserver-fds [R,W]
Internal option make uses to pass the jobserver pipe read and write file descriptor numbers to sub-
makes; see the section PARALLEL MAKE AND THE JOBSERVER for details
-k, --keep-going
Continue as much as possible after an error. While the target that failed, and those that depend on it,
cannot be remade, the other dependencies of these targets can be processed all the same.
-l [load], --load-average[=load]
Specifies that no new jobs (commands) should be started if there are others jobs running and the load
average is at least load (a floating-point number). With no argument, removes a previous load limit.
-L, --check-symlink-times
Use the latest mtime between symlinks and target.
-n, --just-print, --dry-run, --recon
Print the commands that would be executed, but do not execute them (except in certain circumstances).
-o file, --old-file=file, --assume-old=file
Do not remake the file file even if it is older than its dependencies, and do not remake anything on ac‐
count of changes in file. Essentially the file is treated as very old and its rules are ignored.
-O[type], --output-sync[=type]
When running multiple jobs in parallel with -j, ensure the output of each job is collected together
rather than interspersed with output from other jobs. If type is not specified or is target the output
from the entire recipe for each target is grouped together. If type is line the output from each com‐
mand line within a recipe is grouped together. If type is recurse output from an entire recursive make
is grouped together. If type is none output synchronization is disabled.
-p, --print-data-base
Print the data base (rules and variable values) that results from reading the makefiles; then execute as
usual or as otherwise specified. This also prints the version information given by the -v switch (see
below). To print the data base without trying to remake any files, use make -p -f/dev/null.
-q, --question
``Question mode''. Do not run any commands, or print anything; just return an exit status that is zero
if the specified targets are already up to date, nonzero otherwise.
-r, --no-builtin-rules
Eliminate use of the built-in implicit rules. Also clear out the default list of suffixes for suffix
rules.
-R, --no-builtin-variables
Don't define any built-in variables.
-s, --silent, --quiet
Silent operation; do not print the commands as they are executed.
-S, --no-keep-going, --stop
Cancel the effect of the -k option. This is never necessary except in a recursive make where -k might
be inherited from the top-level make via MAKEFLAGS or if you set -k in MAKEFLAGS in your environment.
-t, --touch
Touch files (mark them up to date without really changing them) instead of running their commands. This
is used to pretend that the commands were done, in order to fool future invocations of make.
--trace
Information about the disposition of each target is printed (why the target is being rebuilt and what
commands are run to rebuild it).
-v, --version
Print the version of the make program plus a copyright, a list of authors and a notice that there is no
warranty.
-w, --print-directory
Print a message containing the working directory before and after other processing. This may be useful
for tracking down errors from complicated nests of recursive make commands.
--no-print-directory
Turn off -w, even if it was turned on implicitly.
-W file, --what-if=file, --new-file=file, --assume-new=file
Pretend that the target file has just been modified. When used with the -n flag, this shows you what
would happen if you were to modify that file. Without -n, it is almost the same as running a touch com‐
mand on the given file before running make, except that the modification time is changed only in the
imagination of make.
--warn-undefined-variables
Warn when an undefined variable is referenced.
EXIT STATUS
GNU make exits with a status of zero if all makefiles were successfully parsed and no targets that were built
failed. A status of one will be returned if the -q flag was used and make determines that a target needs to
be rebuilt. A status of two will be returned if any errors were encountered.
SEE ALSO
The full documentation for make is maintained as a Texinfo manual. If the info and make programs are prop‐
erly installed at your site, the command
info make
should give you access to the complete manual. Additionally, the manual is also available online at
https://www.gnu.org/software/make/manual/html_node/index.html
PARALLEL MAKE AND THE JOBSERVER
Using the -j option, the user can instruct make to execute tasks in parallel. By specifying a numeric argu‐
ment to -j the user may specify an upper limit of the number of parallel tasks to be run.
When the build environment is such that a top level make invokes sub-makes (for instance, a style in which
each sub-directory contains its own Makefile ), no individual instance of make knows how many tasks are run‐
ning in parallel, so keeping the number of tasks under the upper limit would be impossible without communica‐
tion between all the make instances running. While solutions like having the top level make serve as a cen‐
tral controller are feasible, or using other synchronization mechanisms like shared memory or sockets can be
created, the current implementation uses a simple shared pipe.
This pipe is created by the top-level make process, and passed on to all the sub-makes. The top level make‐
processwrites N-1 one-byte tokens into the pipe (The top level make is assumed to reserve one token for it‐
self). Whenever any of the make processes (including the top-level make ) needs to run a new task, it reads a
byte from the shared pipe. If there are no tokens left, it must wait for a token to be written back to the
pipe. Once the task is completed, the make process writes a token back to the pipe (and thus, if the tokens
had been exhausted, unblocking the first make process that was waiting to read a token). Since only N-1 to‐
kens were written into the pipe, no more than N tasks can be running at any given time.
If the job to be run is not a sub-make then make will close the jobserver pipe file descriptors before invok‐
ing the commands, so that the command can not interfere with the jobserver, and the command does not find any
unusual file descriptors.
BUGS
See the chapter ``Problems and Bugs'' in The GNU Make Manual.
AUTHOR
This manual page contributed by Dennis Morse of Stanford University. Further updates contributed by Mike
Frysinger. It has been reworked by Roland McGrath. Maintained by Paul Smith.
COPYRIGHT
Copyright © 1992-1993, 1996-2016 Free Software Foundation, Inc. This file is part of GNU make.
GNU Make is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either version 3 of the License, or (at your option)
any later version.
GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the im‐
plied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see
http://www.gnu.org/licenses/.
GNU 28 February 2016 MAKE(1)
pi@raspberrypi:~/Desktop $
$ make -h
用法：make [选项] [目标] ...
选项：
-b, -m 为兼容性而忽略。
-B, --always-make 无条件制作 (make) 所有目标。
-C 目录, --directory=目录 在执行前先切换到 <目录>。
-d 打印大量调试信息。
--debug[=旗标] 打印各种调试信息。
-e, --environment-overrides
环境变量覆盖 makefile 中的变量。
-E 字串, --eval=字串 将 <字串> 作为 makefile 语句估值。
-f 文件, --file=文件, --makefile=文件
从 <文件> 中读入 makefile。
-h, --help 打印该消息并退出。
-i, --ignore-errors 忽略来自命令配方的错误。
-I 目录, --include-dir=目录 在 <目录> 中搜索被包含的 makefile。
-j [N], --jobs[=N] 同时允许 N 个任务；无参数表明允许无限个任务。
-k, --keep-going 当某些目标无法制作时仍然继续。
-l [N], --load-average[=N], --max-load[=N]
在系统负载高于 N 时不启动多任务。
-L, --check-symlink-times 使用软链接及软链接目标中修改时间较晚的一个。
-n, --just-print, --dry-run, --recon
只打印命令配方，不实际执行。
-o 文件, --old-file=文件, --assume-old=文件
将 <文件> 当做很旧，不必重新制作。
-O[类型], --output-sync[=类型]
使用 <类型> 方式同步并行任务输出。
-p, --print-data-base 打印 make 的内部数据库。
-q, --question 不运行任何配方；退出状态说明是否已全部更新。
-r, --no-builtin-rules 禁用内置隐含规则。
-R, --no-builtin-variables 禁用内置变量设置。
-s, --silent, --quiet 不输出配方命令。
--no-silent 对配方进行回显（禁用 --silent 模式）。
-S, --no-keep-going, --stop
关闭 -k。
-t, --touch touch 目标（更新修改时间）而不是重新制作它们。
--trace 打印跟踪信息。
-v, --version 打印 make 的版本号并退出。
-w, --print-directory 打印当前目录。
--no-print-directory 关闭 -w，即使 -w 默认开启。
-W 文件, --what-if=文件, --new-file=文件, --assume-new=文件
将 <文件> 当做最新。
--warn-undefined-variables 当引用未定义变量的时候发出警告。
该程序为 aarch64-unknown-linux-gnu 编译
报告错误到 <[email protected]>
pi@raspberrypi:~/Desktop $
