问题
Want to use __ DATE __ and __ TIME __ as integer for giving automated version to my code in compile time.
#define STRINGIZER(arg) #arg
#define STR_VALUE(arg) STRINGIZER(arg)
#define DATE_as_int_str useD(__DATE__) // What can be done ?
#define TIME_as_int_str useT(__TIME__) // What can be done ?
#define VERSION 1.4
#define COMPLETE_VERSION STR_VALUE(VERSION) "." DATE_as_int_str "." TIME_as_int_str
and get COMPLETE_VERSION as string in a const unsigned char [].
const unsigned char completeVersion[] = ?? COMPLETE_VERSION;
Should output 1.4.1432.2234 something.
One of the possible solution could be but did not work: convert-date-to-unsigned-int
In context of compile time convertint-date-and-time-string-to-just-integers-in-c One can refer expanssion-and-stringification-how-to-get-the-marco-name-not-its-value
回答1:
If you can use a C++ compiler to build the object file that you want to contain your version string, then we can do exactly what you want! The only magic here is that C++ allows you to use expressions to statically initialize an array, while C doesn't. The expressions need to be fully computable at compile time, but these expressions are, so it's no problem.
We build up the version string one byte at a time, and get exactly what we want.
// source file version_num.h
#ifndef VERSION_NUM_H
#define VERSION_NUM_H
#define VERSION_MAJOR 1
#define VERSION_MINOR 4
#endif // VERSION_NUM_H
// source file build_defs.h
#ifndef BUILD_DEFS_H
#define BUILD_DEFS_H
// Example of __DATE__ string: "Jul 27 2012"
// 01234567890
#define BUILD_YEAR_CH0 (__DATE__[ 7])
#define BUILD_YEAR_CH1 (__DATE__[ 8])
#define BUILD_YEAR_CH2 (__DATE__[ 9])
#define BUILD_YEAR_CH3 (__DATE__[10])
#define BUILD_MONTH_IS_JAN (__DATE__[0] == 'J' && __DATE__[1] == 'a' && __DATE__[2] == 'n')
#define BUILD_MONTH_IS_FEB (__DATE__[0] == 'F')
#define BUILD_MONTH_IS_MAR (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'r')
#define BUILD_MONTH_IS_APR (__DATE__[0] == 'A' && __DATE__[1] == 'p')
#define BUILD_MONTH_IS_MAY (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'y')
#define BUILD_MONTH_IS_JUN (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'n')
#define BUILD_MONTH_IS_JUL (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'l')
#define BUILD_MONTH_IS_AUG (__DATE__[0] == 'A' && __DATE__[1] == 'u')
#define BUILD_MONTH_IS_SEP (__DATE__[0] == 'S')
#define BUILD_MONTH_IS_OCT (__DATE__[0] == 'O')
#define BUILD_MONTH_IS_NOV (__DATE__[0] == 'N')
#define BUILD_MONTH_IS_DEC (__DATE__[0] == 'D')
#define BUILD_MONTH_CH0 \
((BUILD_MONTH_IS_OCT || BUILD_MONTH_IS_NOV || BUILD_MONTH_IS_DEC) ? '1' : '0')
#define BUILD_MONTH_CH1 \
( \
(BUILD_MONTH_IS_JAN) ? '1' : \
(BUILD_MONTH_IS_FEB) ? '2' : \
(BUILD_MONTH_IS_MAR) ? '3' : \
(BUILD_MONTH_IS_APR) ? '4' : \
(BUILD_MONTH_IS_MAY) ? '5' : \
(BUILD_MONTH_IS_JUN) ? '6' : \
(BUILD_MONTH_IS_JUL) ? '7' : \
(BUILD_MONTH_IS_AUG) ? '8' : \
(BUILD_MONTH_IS_SEP) ? '9' : \
(BUILD_MONTH_IS_OCT) ? '0' : \
(BUILD_MONTH_IS_NOV) ? '1' : \
(BUILD_MONTH_IS_DEC) ? '2' : \
/* error default */ '?' \
)
#define BUILD_DAY_CH0 ((__DATE__[4] >= '0') ? (__DATE__[4]) : '0')
#define BUILD_DAY_CH1 (__DATE__[ 5])
// Example of __TIME__ string: "21:06:19"
// 01234567
#define BUILD_HOUR_CH0 (__TIME__[0])
#define BUILD_HOUR_CH1 (__TIME__[1])
#define BUILD_MIN_CH0 (__TIME__[3])
#define BUILD_MIN_CH1 (__TIME__[4])
#define BUILD_SEC_CH0 (__TIME__[6])
#define BUILD_SEC_CH1 (__TIME__[7])
#if VERSION_MAJOR > 100
#define VERSION_MAJOR_INIT \
((VERSION_MAJOR / 100) + '0'), \
(((VERSION_MAJOR % 100) / 10) + '0'), \
((VERSION_MAJOR % 10) + '0')
#elif VERSION_MAJOR > 10
#define VERSION_MAJOR_INIT \
((VERSION_MAJOR / 10) + '0'), \
((VERSION_MAJOR % 10) + '0')
#else
#define VERSION_MAJOR_INIT \
(VERSION_MAJOR + '0')
#endif
#if VERSION_MINOR > 100
#define VERSION_MINOR_INIT \
((VERSION_MINOR / 100) + '0'), \
(((VERSION_MINOR % 100) / 10) + '0'), \
((VERSION_MINOR % 10) + '0')
#elif VERSION_MINOR > 10
#define VERSION_MINOR_INIT \
((VERSION_MINOR / 10) + '0'), \
((VERSION_MINOR % 10) + '0')
#else
#define VERSION_MINOR_INIT \
(VERSION_MINOR + '0')
#endif
#endif // BUILD_DEFS_H
// source file main.c
#include "version_num.h"
#include "build_defs.h"
// want something like: 1.4.1432.2234
const unsigned char completeVersion[] =
{
VERSION_MAJOR_INIT,
'.',
VERSION_MINOR_INIT,
'-', 'V', '-',
BUILD_YEAR_CH0, BUILD_YEAR_CH1, BUILD_YEAR_CH2, BUILD_YEAR_CH3,
'-',
BUILD_MONTH_CH0, BUILD_MONTH_CH1,
'-',
BUILD_DAY_CH0, BUILD_DAY_CH1,
'T',
BUILD_HOUR_CH0, BUILD_HOUR_CH1,
':',
BUILD_MIN_CH0, BUILD_MIN_CH1,
':',
BUILD_SEC_CH0, BUILD_SEC_CH1,
'\0'
};
#include <stdio.h>
int main(int argc, char **argv)
{
printf("%s\n", completeVersion);
// prints something similar to: 1.4-V-2013-05-09T15:34:49
}
This isn't exactly the format you asked for, but I still don't fully understand how you want days and hours mapped to an integer. I think it's pretty clear how to make this produce any desired string.
回答2:
Here is a working version of the "build defs". This is similar to my previous answer but I figured out the build month. (You just can't compute build month in a #if statement, but you can use a ternary expression that will be compiled down to a constant.)
Also, according to the documentation, if the compiler cannot get the time of day it will give you question marks for these strings. So I added tests for this case, and made the various macros return an obviously wrong value (99) if this happens.
#ifndef BUILD_DEFS_H
#define BUILD_DEFS_H
// Example of __DATE__ string: "Jul 27 2012"
// Example of __TIME__ string: "21:06:19"
#define COMPUTE_BUILD_YEAR \
( \
(__DATE__[ 7] - '0') * 1000 + \
(__DATE__[ 8] - '0') * 100 + \
(__DATE__[ 9] - '0') * 10 + \
(__DATE__[10] - '0') \
)
#define COMPUTE_BUILD_DAY \
( \
((__DATE__[4] >= '0') ? (__DATE__[4] - '0') * 10 : 0) + \
(__DATE__[5] - '0') \
)
#define BUILD_MONTH_IS_JAN (__DATE__[0] == 'J' && __DATE__[1] == 'a' && __DATE__[2] == 'n')
#define BUILD_MONTH_IS_FEB (__DATE__[0] == 'F')
#define BUILD_MONTH_IS_MAR (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'r')
#define BUILD_MONTH_IS_APR (__DATE__[0] == 'A' && __DATE__[1] == 'p')
#define BUILD_MONTH_IS_MAY (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'y')
#define BUILD_MONTH_IS_JUN (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'n')
#define BUILD_MONTH_IS_JUL (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'l')
#define BUILD_MONTH_IS_AUG (__DATE__[0] == 'A' && __DATE__[1] == 'u')
#define BUILD_MONTH_IS_SEP (__DATE__[0] == 'S')
#define BUILD_MONTH_IS_OCT (__DATE__[0] == 'O')
#define BUILD_MONTH_IS_NOV (__DATE__[0] == 'N')
#define BUILD_MONTH_IS_DEC (__DATE__[0] == 'D')
#define COMPUTE_BUILD_MONTH \
( \
(BUILD_MONTH_IS_JAN) ? 1 : \
(BUILD_MONTH_IS_FEB) ? 2 : \
(BUILD_MONTH_IS_MAR) ? 3 : \
(BUILD_MONTH_IS_APR) ? 4 : \
(BUILD_MONTH_IS_MAY) ? 5 : \
(BUILD_MONTH_IS_JUN) ? 6 : \
(BUILD_MONTH_IS_JUL) ? 7 : \
(BUILD_MONTH_IS_AUG) ? 8 : \
(BUILD_MONTH_IS_SEP) ? 9 : \
(BUILD_MONTH_IS_OCT) ? 10 : \
(BUILD_MONTH_IS_NOV) ? 11 : \
(BUILD_MONTH_IS_DEC) ? 12 : \
/* error default */ 99 \
)
#define COMPUTE_BUILD_HOUR ((__TIME__[0] - '0') * 10 + __TIME__[1] - '0')
#define COMPUTE_BUILD_MIN ((__TIME__[3] - '0') * 10 + __TIME__[4] - '0')
#define COMPUTE_BUILD_SEC ((__TIME__[6] - '0') * 10 + __TIME__[7] - '0')
#define BUILD_DATE_IS_BAD (__DATE__[0] == '?')
#define BUILD_YEAR ((BUILD_DATE_IS_BAD) ? 99 : COMPUTE_BUILD_YEAR)
#define BUILD_MONTH ((BUILD_DATE_IS_BAD) ? 99 : COMPUTE_BUILD_MONTH)
#define BUILD_DAY ((BUILD_DATE_IS_BAD) ? 99 : COMPUTE_BUILD_DAY)
#define BUILD_TIME_IS_BAD (__TIME__[0] == '?')
#define BUILD_HOUR ((BUILD_TIME_IS_BAD) ? 99 : COMPUTE_BUILD_HOUR)
#define BUILD_MIN ((BUILD_TIME_IS_BAD) ? 99 : COMPUTE_BUILD_MIN)
#define BUILD_SEC ((BUILD_TIME_IS_BAD) ? 99 : COMPUTE_BUILD_SEC)
#endif // BUILD_DEFS_H
With the following test code, the above works great:
printf("%04d-%02d-%02dT%02d:%02d:%02d\n", BUILD_YEAR, BUILD_MONTH, BUILD_DAY, BUILD_HOUR, BUILD_MIN, BUILD_SEC);
However, when I try to use those macros with your stringizing macro, it stringizes the literal expression! I don't know of any way to get the compiler to reduce the expression to a literal integer value and then stringize.
Also, if you try to statically initialize an array of values using these macros, the compiler complains with an error: initializer element is not constant message. So you cannot do what you want with these macros.
At this point I'm thinking that your best bet is the Python script that just generates a new include file for you. You can pre-compute anything you want in any format you want. If you don't want Python we can write an AWK script or even a C program.
回答3:
I have a partial answer for you. This is based on what I get from GCC:
__DATE__ gives something like "Jul 27 2012"
__TIME__ gives something like 21:06:19
Put this text in an include file called build_defs.h:
#ifndef BUILD_DEFS_H
#define BUILD_DEFS_H
#define BUILD_YEAR ((__DATE__[7] - '0') * 1000 + (__DATE__[8] - '0') * 100 + (__DATE__[9] - '0') * 10 + __DATE__[10] - '0')
#define BUILD_DATE ((__DATE__[4] - '0') * 10 + __DATE__[5] - '0')
#if 0
#if (__DATE__[0] == 'J' && __DATE__[1] == 'a' && __DATE__[2] == 'n')
#define BUILD_MONTH 1
#elif (__DATE__[0] == 'F' && __DATE__[1] == 'e' && __DATE__[2] == 'b')
#define BUILD_MONTH 2
#elif (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'r')
#define BUILD_MONTH 3
#elif (__DATE__[0] == 'A' && __DATE__[1] == 'p' && __DATE__[2] == 'r')
#define BUILD_MONTH 4
#elif (__DATE__[0] == 'M' && __DATE__[1] == 'a' && __DATE__[2] == 'y')
#define BUILD_MONTH 5
#elif (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'n')
#define BUILD_MONTH 6
#elif (__DATE__[0] == 'J' && __DATE__[1] == 'u' && __DATE__[2] == 'l')
#define BUILD_MONTH 7
#elif (__DATE__[0] == 'A' && __DATE__[1] == 'u' && __DATE__[2] == 'g')
#define BUILD_MONTH 8
#elif (__DATE__[0] == 'S' && __DATE__[1] == 'e' && __DATE__[2] == 'p')
#define BUILD_MONTH 9
#elif (__DATE__[0] == 'O' && __DATE__[1] == 'c' && __DATE__[2] == 't')
#define BUILD_MONTH 10
#elif (__DATE__[0] == 'N' && __DATE__[1] == 'o' && __DATE__[2] == 'v')
#define BUILD_MONTH 11
#elif (__DATE__[0] == 'D' && __DATE__[1] == 'e' && __DATE__[2] == 'c')
#define BUILD_MONTH 12
#else
#error "Could not figure out month"
#endif
#endif
#define BUILD_HOUR ((__TIME__[0] - '0') * 10 + __TIME__[1] - '0')
#define BUILD_MIN ((__TIME__[3] - '0') * 10 + __TIME__[4] - '0')
#define BUILD_SEC ((__TIME__[6] - '0') * 10 + __TIME__[7] - '0')
#endif // BUILD_DEFS_H
I tested the above with GCC on Linux. It all works great, except for the problem that I can't figure out how to get a number for the month. If you check the section that is under #if 0 you will see my attempt to figure out the month. GCC complains with this message:
error: token ""Jul 27 2012"" is not valid in preprocessor expressions
It would be trivial to convert the three-letter month abbreviation into some sort of unique number; just subtract 'A' from the first letter and 'a' from the second and the third, and then convert to a base-26 number or something. But I want to make it evaluate to 1 for January and so on, and I can't figure out how to do that.
EDIT: I just realized that you asked for strings, not expressions that evaluate to integer values.
I tried to use these tricks to build a static string:
#define BUILD_MAJOR 1
#define BUILD_MINOR 4
#define VERSION STRINGIZE(BUILD_MAJOR) "." STRINGIZE(BUILD_MINOR)
char build_str[] = {
BUILD_MAJOR + '0', '.' BUILD_MINOR + '0', '.',
__DATE__[7], __DATE__[8], __DATE__[9], __DATE__[10],
'\0'
};
GCC complains that "initializer element is not constant" for __DATE__.
Sorry, I'm not sure how to help you. Maybe you can try this stuff with your compiler? Or maybe it will give you an idea.
Good luck.
P.S. If you don't need things to be numbers, and you just want a unique build string, it's easy:
const char *build_str = "Version: " VERSION " " __DATE__ " " __TIME__;
With GCC, this results in something like:
Version: 1.4 Jul 27 2012 21:53:59
回答4:
You could always write a simple program in Python or something to create an include file that has simple #define statements with a build number, time, and date. You would then need to run this program before doing a build.
If you like I'll write one and post source here.
If you are lucky, your build tool (IDE or whatever) might have the ability to run an external command, and then you could have the external tool rewrite the include file automatically with each build.
EDIT: Here's a Python program. This writes a file called build_num.h and has an integer build number that starts at 1 and increments each time this program is run; it also writes #define values for the year, month, date, hours, minutes and seconds of the time this program is run. It also has a #define for major and minor parts of the version number, plus the full VERSION and COMPLETE_VERSION that you wanted. (I wasn't sure what you wanted for the date and time numbers, so I went for just concatenated digits from the date and time. You can change this easily.)
Each time you run it, it reads in the build_num.h file, and parses it for the build number; if the build_num.h file does not exist, it starts the build number at 1. Likewise it parses out major and minor version numbers, and if the file does not exist defaults those to version 0.1.
import time
FNAME = "build_num.h"
build_num = None
version_major = None
version_minor = None
DEF_BUILD_NUM = "#define BUILD_NUM "
DEF_VERSION_MAJOR = "#define VERSION_MAJOR "
DEF_VERSION_MINOR = "#define VERSION_MINOR "
def get_int(s_marker, line):
_, _, s = line.partition(s_marker) # we want the part after the marker
return int(s)
try:
with open(FNAME) as f:
for line in f:
if DEF_BUILD_NUM in line:
build_num = get_int(DEF_BUILD_NUM, line)
build_num += 1
elif DEF_VERSION_MAJOR in line:
version_major = get_int(DEF_VERSION_MAJOR, line)
elif DEF_VERSION_MINOR in line:
version_minor = get_int(DEF_VERSION_MINOR, line)
except IOError:
build_num = 1
version_major = 0
version_minor = 1
assert None not in (build_num, version_major, version_minor)
with open(FNAME, 'w') as f:
f.write("#ifndef BUILD_NUM_H\n")
f.write("#define BUILD_NUM_H\n")
f.write("\n")
f.write(DEF_BUILD_NUM + "%d\n" % build_num)
f.write("\n")
t = time.localtime()
f.write("#define BUILD_YEAR %d\n" % t.tm_year)
f.write("#define BUILD_MONTH %d\n" % t.tm_mon)
f.write("#define BUILD_DATE %d\n" % t.tm_mday)
f.write("#define BUILD_HOUR %d\n" % t.tm_hour)
f.write("#define BUILD_MIN %d\n" % t.tm_min)
f.write("#define BUILD_SEC %d\n" % t.tm_sec)
f.write("\n")
f.write("#define VERSION_MAJOR %d\n" % version_major)
f.write("#define VERSION_MINOR %d\n" % version_minor)
f.write("\n")
f.write("#define VERSION \"%d.%d\"\n" % (version_major, version_minor))
s = "%d.%d.%04d%02d%02d.%02d%02d%02d" % (version_major, version_minor,
t.tm_year, t.tm_mon, t.tm_mday, t.tm_hour, t.tm_min, t.tm_sec)
f.write("#define COMPLETE_VERSION \"%s\"\n" % s)
f.write("\n")
f.write("#endif // BUILD_NUM_H\n")
I made all the defines just be integers, but since they are simple integers you can use the standard stringizing tricks to build a string out of them if you like. Also you can trivially extend it to build additional pre-defined strings.
This program should run fine under Python 2.6 or later, including any Python 3.x version. You could run it under an old Python with a few changes, like not using .partition() to parse the string.
回答5:
Short answer (asked version): (format 3.33.20150710.182906)
Please, simple use a makefile with:
MAJOR = 3
MINOR = 33
BUILD = $(shell date +"%Y%m%d.%H%M%S")
VERSION = "\"$(MAJOR).$(MINOR).$(BUILD)\""
CPPFLAGS = -DVERSION=$(VERSION)
program.x : source.c
gcc $(CPPFLAGS) source.c -o program.x
and if you don't want a makefile, shorter yet, just compile with:
gcc source.c -o program.x -DVERSION=\"2.22.$(date +"%Y%m%d.%H%M%S")\"
Short answer (suggested version): (format 150710.182906)
Use a double for version number:
MakeFile:
VERSION = $(shell date +"%g%m%d.%H%M%S")
CPPFLAGS = -DVERSION=$(VERSION)
program.x : source.c
gcc $(CPPFLAGS) source.c -o program.x
Or a simple bash command:
$ gcc source.c -o program.x -DVERSION=$(date +"%g%m%d.%H%M%S")
Tip:
Still don't like makefile or is it just for a not-so-small test program? Add this line:
export CPPFLAGS='-DVERSION='$(date +"%g%m%d.%H%M%S")
to your ~/.profile, and remember compile with gcc $CPPFLAGS ...
Long answer:
I know this question is older, but I have a small contribution to make. Best practice is always automatize what otherwise can became a source of error (or oblivion).
I was used to a function that created the version number for me. But I prefer this function to return a float. My version number can be printed by: printf("%13.6f\n", version()); which issues something like: 150710.150411 (being Year (2 digits) month day DOT hour minute seconds).
But, well, the question is yours. If you prefer "major.minor.date.time", it will have to be a string. (Trust me, double is better. If you insist in a major, you can still use double if you set the major and let the decimals to be date+time, like: major.datetime = 1.150710150411
Lets get to business. The example bellow will work if you compile as usual, forgetting to set it, or use -DVERSION to set the version directly from shell, but better of all, I recommend the third option: use a makefile.
Three forms of compiling and the results:
Using make:
beco> make program.x
gcc -Wall -Wextra -g -O0 -ansi -pedantic-errors -c -DVERSION="\"3.33.20150710.045829\"" program.c -o program.o
gcc program.o -o program.x
Running:
__DATE__: 'Jul 10 2015'
__TIME__: '04:58:29'
VERSION: '3.33.20150710.045829'
Using -DVERSION:
beco> gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors -DVERSION=\"2.22.$(date +"%Y%m%d.%H%M%S")\"
Running:
__DATE__: 'Jul 10 2015'
__TIME__: '04:58:37'
VERSION: '2.22.20150710.045837'
Using the build-in function:
beco> gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors
Running:
__DATE__: 'Jul 10 2015'
__TIME__: '04:58:43'
VERSION(): '1.11.20150710.045843'
Source code
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4
5 #define FUNC_VERSION (0)
6 #ifndef VERSION
7 #define MAJOR 1
8 #define MINOR 11
9 #define VERSION version()
10 #undef FUNC_VERSION
11 #define FUNC_VERSION (1)
12 char sversion[]="9999.9999.20150710.045535";
13 #endif
14
15 #if(FUNC_VERSION)
16 char *version(void);
17 #endif
18
19 int main(void)
20 {
21
22 printf("__DATE__: '%s'\n", __DATE__);
23 printf("__TIME__: '%s'\n", __TIME__);
24
25 printf("VERSION%s: '%s'\n", (FUNC_VERSION?"()":""), VERSION);
26 return 0;
27 }
28
29 /* String format: */
30 /* __DATE__="Oct 8 2013" */
31 /* __TIME__="00:13:39" */
32
33 /* Version Function: returns the version string */
34 #if(FUNC_VERSION)
35 char *version(void)
36 {
37 const char data[]=__DATE__;
38 const char tempo[]=__TIME__;
39 const char nomes[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
40 char omes[4];
41 int ano, mes, dia, hora, min, seg;
42
43 if(strcmp(sversion,"9999.9999.20150710.045535"))
44 return sversion;
45
46 if(strlen(data)!=11||strlen(tempo)!=8)
47 return NULL;
48
49 sscanf(data, "%s %d %d", omes, &dia, &ano);
50 sscanf(tempo, "%d:%d:%d", &hora, &min, &seg);
51 mes=(strstr(nomes, omes)-nomes)/3+1;
52 sprintf(sversion,"%d.%d.%04d%02d%02d.%02d%02d%02d", MAJOR, MINOR, ano, mes, dia, hora, min, seg);
53
54 return sversion;
55 }
56 #endif
Please note that the string is limited by MAJOR<=9999 and MINOR<=9999. Of course, I set this high value that will hopefully never overflow. But using double is still better (plus, it's completely automatic, no need to set MAJOR and MINOR by hand).
Now, the program above is a bit too much. Better is to remove the function completely, and guarantee that the macro VERSION is defined, either by -DVERSION directly into GCC command line (or an alias that automatically add it so you can't forget), or the recommended solution, to include this process into a makefile.
Here it is the makefile I use:
MakeFile source:
1 MAJOR = 3
2 MINOR = 33
3 BUILD = $(shell date +"%Y%m%d.%H%M%S")
4 VERSION = "\"$(MAJOR).$(MINOR).$(BUILD)\""
5 CC = gcc
6 CFLAGS = -Wall -Wextra -g -O0 -ansi -pedantic-errors
7 CPPFLAGS = -DVERSION=$(VERSION)
8 LDLIBS =
9
10 %.x : %.c
11 $(CC) $(CFLAGS) $(CPPFLAGS) $(LDLIBS) $^ -o $@
A better version with DOUBLE
Now that I presented you "your" preferred solution, here it is my solution:
Compile with (a) makefile or (b) gcc directly:
(a) MakeFile:
VERSION = $(shell date +"%g%m%d.%H%M%S")
CC = gcc
CFLAGS = -Wall -Wextra -g -O0 -ansi -pedantic-errors
CPPFLAGS = -DVERSION=$(VERSION)
LDLIBS =
%.x : %.c
$(CC) $(CFLAGS) $(CPPFLAGS) $(LDLIBS) $^ -o $@
(b) Or a simple bash command:
$ gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors -DVERSION=$(date +"%g%m%d.%H%M%S")
Source code (double version):
#ifndef VERSION
#define VERSION version()
#endif
double version(void);
int main(void)
{
printf("VERSION%s: '%13.6f'\n", (FUNC_VERSION?"()":""), VERSION);
return 0;
}
double version(void)
{
const char data[]=__DATE__;
const char tempo[]=__TIME__;
const char nomes[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
char omes[4];
int ano, mes, dia, hora, min, seg;
char sversion[]="130910.001339";
double fv;
if(strlen(data)!=11||strlen(tempo)!=8)
return -1.0;
sscanf(data, "%s %d %d", omes, &dia, &ano);
sscanf(tempo, "%d:%d:%d", &hora, &min, &seg);
mes=(strstr(nomes, omes)-nomes)/3+1;
sprintf(sversion,"%04d%02d%02d.%02d%02d%02d", ano, mes, dia, hora, min, seg);
fv=atof(sversion);
return fv;
}
Note: this double function is there only in case you forget to define macro VERSION. If you use a makefile or set an alias gcc gcc -DVERSION=$(date +"%g%m%d.%H%M%S"), you can safely delete this function completely.
Well, that's it. A very neat and easy way to setup your version control and never worry about it again!
回答6:
For anyone just looking to replace the extra ' ' (space) if day is less than 10 then use:
#define BUILD_DATE (char const[]) { __DATE__[0], __DATE__[1], __DATE__[2], __DATE__[3], (__DATE__[4] == ' ' ? '0' : __DATE__[4]), __DATE__[5], __DATE__[6], __DATE__[7], __DATE__[8], __DATE__[9], __DATE__[10], __DATE__[11] }
Output: Sep 06 2019
回答7:
it is very simple....
[in make file]
==== 1 ===================
OBJS = ....\
version.o <<== add to your obj lists
==== 2 ===================
DATE = $(shell date +'char szVersionStr[20] = "%Y-%m-%d %H:%M:%S";') <<== add
all:version $(ProgramID) <<== version add at first
version: <<== add
echo '$(DATE)' > version.c <== add ( create version.c file)
[in program]
=====3 =============
extern char szVersionStr[20];
[ using ]
=== 4 ====
printf( "Version: %s\n", szVersionStr );
来源：https://stackoverflow.com/questions/11697820/how-to-use-date-and-time-predefined-macros-in-as-two-integers-then-stri