---
name: "gd_strings"
section: "3"
platform: "linux"
package: "libgetdata-doc"
version: "0.11.0-15"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/gd_strings"
---

# gd\_strings(3)

retrieve a list of string values from a Dirfile

## NAME

gd\_strings — retrieve a list of string values from a Dirfile

## SYNOPSIS

**#include \<getdata.h\>**

**const char \*\*gd\_strings(DIRFILE \****dirfile***);**

**const char \*\*gd\_mstrings(DIRFILE \****dirfile***, const char \****parent***);**

## DESCRIPTION

The **gd\_strings**() function queries a [dirfile(5)](/dirfile/5.md) database specified by *dirfile* and compiles a read-only list of values of the all **STRING** type fields defined in the database, excluding /META subfields.

The **gd\_mstrings**() function produces the same list, but for **STRING** meta subfields of the indicated *parent* field.

The  *dirfile* argument must point to a valid DIRFILE object previously created by a call to [**gd\_open**(3)](/gd_open/3.md).

## RETURN VALUE

Upon successful completion, **gd\_strings**() returns a pointer to an array of strings containing the values of all the **STRING** fields defined in the dirfile database.  Similarly, **gd\_mstrings**() returns a pointer to an array of strings containing the values of all the **STRING** metafields under *parent*.

The returned array is terminated by a NULL pointer.  A valid pointer is always returned if this function does not encounter an error.  If there are no string values to return, a pointer to an array consisting of only the NULL pointer is returned.

The array returned will be de-allocated by a call to [**gd\_close**(3)](/gd_close/3.md) and should not be de-allocated by the caller.  The list returned should not be assumed to be in any particular order, although it is guaranteed to be in the same order as the list of **STRING** fields returned by [**gd\_field\_list\_by\_type**(3)](/gd_field_list_by_type/3.md). The array is terminated by a NULL pointer.  The number of strings in the array can be obtained from a call to [**gd\_nfields\_by\_type**(3)](/gd_nfields_by_type/3.md).

The caller may not modify any strings in the array, or the array itself.  Doing so may cause database corruption.  The pointer returned is guaranteed to be valid until **gd\_strings**() or **gd\_mstrings**() is called again with the same arguments, or until the array is de-allocated by a call to [**gd\_close**(3)](/gd_close/3.md) or [**gd\_discard**(3)](/gd_discard/3.md).

On error, these functions return NULL and store a negative-valued error code in the **DIRFILE** object which may be retrieved by a subsequent call to [**gd\_error**(3)](/gd_error/3.md). Possible error codes are:\
  .TP 8 **GD\_E\_ALLOC** The library was unable to allocate memory.\
  .TP 8 **GD\_E\_BAD\_CODE** (**gd\_mstrings**() only) The supplied parent field code was not found, or referred to a metafield itself.\
  .TP 8 **GD\_E\_BAD\_DIRFILE** The supplied dirfile was invalid.

A descriptive error string for the error may be obtained by calling [**gd\_error\_string**(3)](/gd_error_string/3.md).

## HISTORY

The **get\_strings**() function appeared in GetData-0.3.0.

The **get\_mstrings**() function appeared in GetData-0.4.0.

In GetData-0.7.0, these functions were renamed to **gd\_strings**() and **gd\_mstrings**().

## SEE ALSO

[**gd\_error**(3)](/gd_error/3.md), [**gd\_error\_string**(3)](/gd_error_string/3.md), [**gd\_field\_list\_by\_type**(3)](/gd_field_list_by_type/3.md), [**gd\_mstrings**(3)](/gd_mstrings/3.md), [**gd\_nfields\_by\_type**(3)](/gd_nfields_by_type/3.md), [**gd\_open**(3)](/gd_open/3.md), **gd\_string**(3), [dirfile(5)](/dirfile/5.md)