Provided by: libgetdata-doc_0.11.0-4_all
gd_alter_spec, gd_malter_spec — modify a field in a Dirfile
#include <getdata.h> int gd_alter_spec(DIRFILE *dirfile, const char *line, int recode); int gd_malter_spec(DIRFILE *dirfile, const char *line, const char *parent, int recode);
The gd_alter_spec() function modifies the field described by the field specification line in line to the dirfile specified by dirfile. The gd_malter_spec() function behaves similarly, but modifies the metafield under the field indicated by the field code parent. Field specification lines are described in detail in dirfile-format(5). The name of the field to be modified, which must already exist, will be obtained from the field specification line. When adding a metafield, line should only contain a field specification, and not a /META directive. If the modified field is of type RAW and the recode argument is non-zero, the binary file associated with the field will be converted for changes in data type and samples-per- frame. In this case, the field's I/O pointer will be reset to the beginning-of-frame. If recode is zero, no binary file conversion will take place. If the modified field is of type LINTERP and the recode argument is non-zero, the look-up table file will be moved if line specifies a different path, overwriting an existing file with the new pathname, if present. If the field specified by field_code is of type other than RAW or LINTERP, the recode argument is ignored. Passing these functions a directive line instead of a field specification line will result in a syntax error. These functions never call the registered parser callback function, even if line contains a syntax error.
On success, gd_alter_spec() and gd_malter_spec() return zero. On error, it returns a negative-valued error code. Possible error codes are: GD_E_ACCMODE The specified dirfile was opened read-only. GD_E_ALLOC The library was unable to allocate memory. GD_E_BAD_CODE The field specified in line was not found, or the parent field code was not found. GD_E_BAD_DIRFILE The supplied dirfile was invalid. GD_E_FORMAT A syntax error was encountered in line. GD_E_IO An I/O error occurred while translating the binary file associated with a modified RAW field, or an I/O error occurred while attempting to rename a LINTERP table file. GD_E_LINE_TOO_LONG The supplied line was longer than the parser was able to deal with. Line lengths are limited by the storage size of size_t. GD_E_PROTECTED The metadata of the fragment was protected from change. Or, a request to translate the binary file associated with a RAW field was attempted, but the data of the fragment was protected. GD_E_UNKNOWN_ENCODING The encoding scheme of the indicated format specification fragment is not known to the library. As a result, the library was unable to translate the binary file be associated with a modified RAW field. GD_E_UNSUPPORTED The encoding scheme of the indicated format specification fragment does not support translating the empty binary file associated with a modified RAW field. The error code is also stored in the DIRFILE object and may be retrieved after this function returns by calling gd_error(3). A descriptive error string for the error may be obtained by calling gd_error_string(3).
The functions dirfile_alter_spec() and dirfile_malter_spec() appeared in GetData-0.5.0. In GetData-0.7.0, these functions were renamed to gd_alter_spec() and gd_malter_spec.() In GetData-0.10.0, the error return from these functions changed from -1 to a negative- valued error code.
Any of the gd_alter_<entry-type> functions (e.g., gd_alter_bit(3)), gd_alter_spec(3), gd_error(3), gd_error_string(3), gd_metaflush(3), gd_open(3), dirfile-format(5)