Given a cron expression and a date, you can get the next date which satisfies the cron expression.
Supports cron expressions with seconds field. Based on implementation of CronSequenceGenerator from Spring Framework.
Compiles and should work on Linux (GCC/Clang), Mac OS (Clang), Windows (MSVC), Android NDK, iOS, Raspberry Pi and possibly on other platforms with time.h support.
Supports compilation in C (89) and in C++ modes.
#include "ccronexpr.h"
const char* err = NULL;
cron_expr* expr = cron_parse_expr("0 */2 1-4 * * *", &err);
if (err) ... /* invalid expression */
time_t cur = time(NULL);
time_t next = cron_next(expr, cur);
...
cron_expr_free(expr);
gcc ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c89 && ./a.out
g++ ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c++11 && ./a.out
g++ ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c++11 -DCRON_COMPILE_AS_CXX && ./a.out
clang ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c89 && ./a.out
clang++ ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c++11 && ./a.out
clang++ ccronexpr.c ccronexpr_test.c -I. -Wall -Wextra -std=c++11 -DCRON_COMPILE_AS_CXX && ./a.out
cl ccronexpr.c ccronexpr_test.c /W4 /D_CRT_SECURE_NO_WARNINGS && ccronexpr.exe
Expression, input date, next date:
"*/15 * 1-4 * * *", "2012-07-01_09:53:50", "2012-07-02_01:00:00"
"0 */2 1-4 * * *", "2012-07-01_09:00:00", "2012-07-02_01:00:00"
"0 0 7 ? * MON-FRI", "2009-09-26_00:42:55", "2009-09-28_07:00:00"
"0 30 23 30 1/3 ?", "2011-04-30_23:30:00", "2011-07-30_23:30:00"
See more examples in tests.
This implementation does not support explicit timezones handling. By default all dates are processed as UTC (GMT) dates without timezone infomation.
To use local dates (current system timezone) instead of GMT compile with -DCRON_USE_LOCAL_TIME.
This project is released under the Apache License 2.0
2016-06-17
- use thread-safe versions of
gmtimeandlocaltime
2015-02-28
- initial public version