regex.3: Add example program
Commit Message
$ gcc -Wall -Wextra -Werror -pedantic regex.c -o regex
$ ./regex
String = "1) John Driverhacker;
2) John Doe;
3) John Foo;
"
#0 match:
rm_so = 25; rm_eo = 32; len = 7
substring = "John Do"
#1 match:
rm_so = 6; rm_eo = 14; len = 8
substring = "John Foo"
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
---
Hello Michael,
Here's the example for regex.3 :-}
Best regards,
Alex
man3/regex.3 | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
Comments
I realized now that the output is a bit weird:
I'm printing the offset incorrectly (except for the first match).
I'll fix it in a few minutes.
Thanks,
Alex
On 10/17/20 3:13 PM, Alejandro Colomar wrote:
> $ gcc -Wall -Wextra -Werror -pedantic regex.c -o regex
> $ ./regex
> String = "1) John Driverhacker;
> 2) John Doe;
> 3) John Foo;
> "
> #0 match:
> rm_so = 25; rm_eo = 32; len = 7
> substring = "John Do"
> #1 match:
> rm_so = 6; rm_eo = 14; len = 8
> substring = "John Foo"
>
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
> ---
>
> Hello Michael,
>
> Here's the example for regex.3 :-}
>
> Best regards,
>
> Alex
>
>
> man3/regex.3 | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/man3/regex.3 b/man3/regex.3
> index 7c5132995..94da88b7e 100644
> --- a/man3/regex.3
> +++ b/man3/regex.3
> @@ -337,6 +337,50 @@ T} Thread safety MT-Safe
> .TE
> .SH CONFORMING TO
> POSIX.1-2001, POSIX.1-2008.
> +.SH EXAMPLES
> +.EX
> +#include <stddef.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <regex.h>
> +
> +#define ARRAY_SIZE(arr) (sizeof((arr)) / sizeof((arr)[0]))
> +
> +static const char *const str =
> + "1) John Driverhacker;\en2) John Doe;\en3) John Foo;\en";
> +static const char *const re = "John.*o";
> +
> +int main(void)
> +{
> + static const char *s = str;
> + regex_t regex;
> + regmatch_t pmatch[1];
> + regoff_t len;
> +
> + if (regcomp(®ex, re, REG_NEWLINE))
> + exit(EXIT_FAILURE);
> +
> + printf("String = \\"%s\\"\en", str);
> +
> + for (ptrdiff_t i = 0; ; i++) {
> + if (regexec(®ex, s, ARRAY_SIZE(pmatch), pmatch, 0))
> + break;
> +
> + len = pmatch[0].rm_eo \- pmatch[0].rm_so;
> + printf("#%td match:\en", i);
> + printf("rm_so = %jd; rm_eo = %jd; len = %jd\en",
> + (intmax_t) pmatch[0].rm_so,
> + (intmax_t) pmatch[0].rm_eo,
> + (intmax_t) len);
> + printf("substring = \\"%.*s\\"\en", len, s + pmatch[0].rm_so);
> +
> + s += pmatch[0].rm_eo;
> + }
> +
> + exit(EXIT_SUCCESS);
> +}
> +.EE
> .SH SEE ALSO
> .BR grep (1),
> .BR regex (7)
>
@@ -337,6 +337,50 @@ T} Thread safety MT-Safe
.TE
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
+.SH EXAMPLES
+.EX
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <regex.h>
+
+#define ARRAY_SIZE(arr) (sizeof((arr)) / sizeof((arr)[0]))
+
+static const char *const str =
+ "1) John Driverhacker;\en2) John Doe;\en3) John Foo;\en";
+static const char *const re = "John.*o";
+
+int main(void)
+{
+ static const char *s = str;
+ regex_t regex;
+ regmatch_t pmatch[1];
+ regoff_t len;
+
+ if (regcomp(®ex, re, REG_NEWLINE))
+ exit(EXIT_FAILURE);
+
+ printf("String = \\"%s\\"\en", str);
+
+ for (ptrdiff_t i = 0; ; i++) {
+ if (regexec(®ex, s, ARRAY_SIZE(pmatch), pmatch, 0))
+ break;
+
+ len = pmatch[0].rm_eo \- pmatch[0].rm_so;
+ printf("#%td match:\en", i);
+ printf("rm_so = %jd; rm_eo = %jd; len = %jd\en",
+ (intmax_t) pmatch[0].rm_so,
+ (intmax_t) pmatch[0].rm_eo,
+ (intmax_t) len);
+ printf("substring = \\"%.*s\\"\en", len, s + pmatch[0].rm_so);
+
+ s += pmatch[0].rm_eo;
+ }
+
+ exit(EXIT_SUCCESS);
+}
+.EE
.SH SEE ALSO
.BR grep (1),
.BR regex (7)