pkgs/initscripts/src/shvar.h

   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
  53 /* Create the file <name>, return shvarFile on success, NULL on failure */
  54 shvarFile *
  55 svCreateFile(const char *name);
  56
  57 /* Open the file <name>, return shvarFile on success, NULL on failure */
  58 shvarFile *
  59 svNewFile(const char *name);
  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 *
  66 svGetValue(shvarFile *s, const char *key);
  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
  73 svTrueValue(shvarFile *s, const char *key, int def);
  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
  81 svSetValue(shvarFile *s, const char *key, const char *value);
  82
  83
  84 /* Write the current contents iff modified.  Returns -1 on error
  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 */