[projects/rc-scripts.git] / src / shvar.h

/*
 * shvar.h
 *
 * Interface for non-destructively reading/writing files containing
 * only shell variable declarations and full-line comments.
 *
 * Includes explicit inheritance mechanism intended for use with
 * Red Hat Linux ifcfg-* files.  There is no protection against
 * inheritance loops; they will generally cause stack overflows.
 * Furthermore, they are only intended for one level of inheritance;
 * the value setting algorithm assumes this.
 *
 * Copyright 1999 Red Hat, Inc.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#ifndef _SHVAR_H
#define _SHVAR_H

#include <glib.h>

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

typedef struct _shvarFile shvarFile;
struct _shvarFile {
	char		*fileName;	/* read-only */
	int		fd;		/* read-only */
	char		*arena;		/* ignore */
	GList		*lineList;	/* read-only */
	GList		*freeList;	/* ignore */
	GList		*current;	/* set implicitly or explicitly,
					   points to element of lineList */
	shvarFile	*parent;	/* set explicitly */
	int		modified;	/* ignore */
};


/* Create the file <name>, return shvarFile on success, NULL on failure */
shvarFile *
svCreateFile(const char *name);

/* Open the file <name>, return shvarFile on success, NULL on failure */
shvarFile *
svNewFile(const char *name);

/* Get the value associated with the key, and leave the current pointer
 * pointing at the line containing the value.  The char* returned MUST
 * be freed by the caller.
 */
char *
svGetValue(shvarFile *s, const char *key);

/* return 1 if <key> resolves to any truth value (e.g. "yes", "y", "true")
 * return 0 if <key> resolves to any non-truth value (e.g. "no", "n", "false")
 * return <def> otherwise
 */
int
svTrueValue(shvarFile *s, const char *key, int def);

/* Set the variable <key> equal to the value <value>.
 * If <key> does not exist, and the <current> pointer is set, append
 * the key=value pair after that line.  Otherwise, prepend the pair
 * to the top of the file.
 */
void
svSetValue(shvarFile *s, const char *key, const char *value);


/* Write the current contents iff modified.  Returns -1 on error
 * and 0 on success.  Do not write if no values have been modified.
 * The mode argument is only used if creating the file, not if
 * re-writing an existing file, and is passed unchanged to the
 * open() syscall.
 */
int
svWriteFile(shvarFile *s, int mode);

/* Close the file descriptor (if open) and delete the shvarFile.
 * Returns -1 on error and 0 on success.
 */
int
svCloseFile(shvarFile *s);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* ! _SHVAR_H */
Commit	Line	Data
458f14b7 AM	1	/*
	2	* shvar.h
	3	*
	4	* Interface for non-destructively reading/writing files containing
	5	* only shell variable declarations and full-line comments.
	6	*
	7	* Includes explicit inheritance mechanism intended for use with
	8	* Red Hat Linux ifcfg-* files. There is no protection against
	9	* inheritance loops; they will generally cause stack overflows.
	10	* Furthermore, they are only intended for one level of inheritance;
	11	* the value setting algorithm assumes this.
	12	*
	13	* Copyright 1999 Red Hat, Inc.
	14	*
	15	* This is free software; you can redistribute it and/or modify it
	16	* under the terms of the GNU General Public License as published by
	17	* the Free Software Foundation; either version 2 of the License, or
	18	* (at your option) any later version.
	19	*
	20	* This program is distributed in the hope that it will be useful, but
	21	* WITHOUT ANY WARRANTY; without even the implied warranty of
	22	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	23	* General Public License for more details.
	24	*
	25	* You should have received a copy of the GNU General Public License
	26	* along with this program; if not, write to the Free Software
	27	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	28	*
	29	*/
	30	#ifndef _SHVAR_H
	31	#define _SHVAR_H
	32
	33	#include <glib.h>
	34
	35	#ifdef __cplusplus
	36	extern "C" {
	37	#endif /* __cplusplus */
	38
	39	typedef struct _shvarFile shvarFile;
	40	struct _shvarFile {
	41	char fileName; / read-only */
	42	int fd; /* read-only */
	43	char arena; / ignore */
	44	GList lineList; / read-only */
	45	GList freeList; / ignore */
	46	GList current; / set implicitly or explicitly,
	47	points to element of lineList */
	48	shvarFile parent; / set explicitly */
	49	int modified; /* ignore */
	50	};
	51
	52
de1fc6ce JR	53	/* Create the file <name>, return shvarFile on success, NULL on failure */
	54	shvarFile *
	55	svCreateFile(const char *name);
	56
458f14b7 AM	57	/* Open the file <name>, return shvarFile on success, NULL on failure */
458f14b7 AM	58	shvarFile *
de1fc6ce	59	svNewFile(const char *name);
458f14b7 AM	60
	61	/* Get the value associated with the key, and leave the current pointer
	62	* pointing at the line containing the value. The char* returned MUST
	63	* be freed by the caller.
	64	*/
	65	char *
de1fc6ce	66	svGetValue(shvarFile s, const char key);
458f14b7 AM	67
	68	/* return 1 if <key> resolves to any truth value (e.g. "yes", "y", "true")
	69	* return 0 if <key> resolves to any non-truth value (e.g. "no", "n", "false")
	70	* return <def> otherwise
	71	*/
	72	int
de1fc6ce	73	svTrueValue(shvarFile s, const char key, int def);
458f14b7 AM	74
	75	/* Set the variable <key> equal to the value <value>.
	76	* If <key> does not exist, and the <current> pointer is set, append
	77	* the key=value pair after that line. Otherwise, prepend the pair
	78	* to the top of the file.
	79	*/
	80	void
de1fc6ce	81	svSetValue(shvarFile s, const char key, const char *value);
458f14b7 AM	82
458f14b7 AM	83
163dcb78	84	/* Write the current contents iff modified. Returns -1 on error
458f14b7 AM	85	* and 0 on success. Do not write if no values have been modified.
	86	* The mode argument is only used if creating the file, not if
	87	* re-writing an existing file, and is passed unchanged to the
	88	* open() syscall.
	89	*/
	90	int
	91	svWriteFile(shvarFile *s, int mode);
	92
	93	/* Close the file descriptor (if open) and delete the shvarFile.
	94	* Returns -1 on error and 0 on success.
	95	*/
	96	int
	97	svCloseFile(shvarFile *s);
	98
	99	#ifdef __cplusplus
	100	}
	101	#endif /* __cplusplus */
	102
	103	#endif /* ! _SHVAR_H */