[Libguestfs] [nbdkit PATCH v2 3/5] utils: Add nbdkit_parse_bool

Parses the same set of boolean parameters as libguestfs: https://github.com/libguestfs/libguestfs/blob/dd665e4bb/common/utils/util... with permission from Rich Jones to relax his code to BSD licensing: https://www.redhat.com/archives/libguestfs/2018-November/msg00094.html Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- docs/nbdkit-plugin.pod | 11 +++++++++++ include/nbdkit-common.h | 1 + src/utils.c | 25 +++++++++++++++++++++++++ 3 files changed, 37 insertions(+) diff --git a/docs/nbdkit-plugin.pod b/docs/nbdkit-plugin.pod index 594f2f3..4754d2c 100644 --- a/docs/nbdkit-plugin.pod +++ b/docs/nbdkit-plugin.pod @@ -763,6 +763,17 @@ size strings such as "100M" into the size in bytes. C<str> can be a string in a number of common formats. The function returns the size in bytes. If there was an error, it returns C<-1>. +=head1 PARSING BOOLEAN PARAMETERS + +Use the C<nbdkit_parse_bool> utility function to parse human-readable +strings such as "on" into a boolean value. + + int nbdkit_parse_bool (const char *str); + +C<str> can be a string containing a case-insensitive form of various +common toggle values. The function returns 0 or 1 if the parse was +successful. If there was an error, it returns C<-1>. + =head1 READING PASSWORDS The C<nbdkit_read_password> utility function can be used to read diff --git a/include/nbdkit-common.h b/include/nbdkit-common.h index 47d2c47..9295b8a 100644 --- a/include/nbdkit-common.h +++ b/include/nbdkit-common.h @@ -66,6 +66,7 @@ extern void nbdkit_vdebug (const char *msg, va_list args); extern char *nbdkit_absolute_path (const char *path); extern int64_t nbdkit_parse_size (const char *str); +extern int nbdkit_parse_bool (const char *str); extern int nbdkit_read_password (const char *value, char **password); extern char *nbdkit_realpath (const char *path); diff --git a/src/utils.c b/src/utils.c index c9e1e14..18011fd 100644 --- a/src/utils.c +++ b/src/utils.c @@ -158,6 +158,31 @@ nbdkit_parse_size (const char *str) return size * scale; } +/* Parse a string as a boolean, or return -1 after reporting the error. + */ +int +nbdkit_parse_bool (const char *str) +{ + if (!strcmp (str, "1") || + !strcasecmp (str, "true") || + !strcasecmp (str, "t") || + !strcasecmp (str, "yes") || + !strcasecmp (str, "y") || + !strcasecmp (str, "on")) + return 1; + + if (!strcmp (str, "0") || + !strcasecmp (str, "false") || + !strcasecmp (str, "f") || + !strcasecmp (str, "no") || + !strcasecmp (str, "n") || + !strcasecmp (str, "off")) + return 0; + + nbdkit_error ("could not decipher boolean (%s)", str); + return -1; +} + /* Read a password from configuration value. */ int nbdkit_read_password (const char *value, char **password) -- 2.17.2