NAME

DtDtsDataToDataType — get the data type for a set of data

SYNOPSIS

#include &<Dt/Dts.h>
char *DtDtsDataToDataType(
const char *filepath,
const void *buffer,
const int size,
const struct stat *stat_buff,
const char *link_path,
const struct stat *link_stat_buff,
const char *opt_name);

DESCRIPTION

The DtDtsDataToDataType function determines the data type of a set of data, based on the information given in the non- NULL pointer arguments to the function. The function gathers any additional information, if it is needed, to compensate for the NULL arguments. For example, if the filepath argument is given, but the stat_buff argument is NULL and a stat_buff value is required to determine the data type, DtDtsDataToDataType calls the stat(2) function to obtain the information.

The filepath argument is the pathname of a file.

The buffer argument is a pointer to the buffer of the data to be typed.

The size argument is the size of the buffer in bytes.

The stat_buff argument is the buffer returned from a stat(2) or fstat(3) call for use in typing.

The link_path argument is the pathname of the target file pointed to by a symbolic link.

The link_stat_buff argument is the buffer returned from an lstat(2) call for use in typing.

The opt_name argument can be used to specify a name to be associated with the buffer. If the opt_name argument is not NULL, it is used as a pseudo file name in typing; otherwise, certain attributes may be returned as NULL because the filename components could not be determined.

RETURN VALUE

Upon successful completion, the DtDtsDataToDataType function returns a pointer to a data type string, or NULL if no value could be determined.

APPLICATION USAGE

The DtDtsDataToDataType function is generally used by applications such as file managers to improve performance. Typical applications should probably use DtDtsFileToDataType(3) or DtDtsBufferToDataType(3) instead.

The DtDtsBuffer* functions assume that the buffer is readable and writable by the user, group and other file classes and select a type accordingly. An application requiring a type based on read-only permissions should use DtDtsDataToDataType with a stat_buff value created for this purpose: all fields should NULL except for the st_mode field, which should be set to:

S_IFREG | S_IROTH | S_IRGRP | S_IRUSR

SEE ALSO

Dt/Dts.h, DtDtsLoadDataTypes(3), DtDtsFileToDataType(3), DtDtsBufferToDataType(3), fstat(3), lstat(2), stat(2).