src/protocols/zephyr/ZVariables.c

   1 /* This file is part of the Project Athena Zephyr Notification System.
   2  * It contains source for the ZGetVariable, ZSetVariable, and ZUnsetVariable
   3  * functions.
   4  *
   5  *      Created by:     Robert French
   6  *
   7  *      $Source$
   8  *      $Author: warmenhoven $
   9  *
  10  *      Copyright (c) 1987 by the Massachusetts Institute of Technology.
  11  *      For copying and distribution information, see the file
  12  *      "mit-copyright.h".
  13  */
  14 /* $Header$ */
  15
  16 #ifndef lint
  17 static char rcsid_ZVariables_c[] = "$Header$";
  18 #endif
  19
  20 #include <internal.h>
  21
  22 #include <ctype.h>
  23 #include <pwd.h>
  24
  25 static int get_localvarfile __P((char *bfr));
  26 static char *get_varval __P((char *fn, char *val));
  27 static int varline __P((char *bfr, char *var));
  28
  29 char *ZGetVariable(var)
  30     char *var;
  31 {
  32     char varfile[128], *ret;
  33     char *get_varval();
  34
  35     if (get_localvarfile(varfile))
  36         return ((char *)0);
  37
  38     if ((ret = get_varval(varfile, var)) != ZERR_NONE)
  39         return (ret);
  40
  41     sprintf(varfile, "%s/zephyr.vars", CONFDIR);
  42     return (get_varval(varfile, var));
  43 }
  44
  45 Code_t ZSetVariable(var, value)
  46     char *var;
  47     char *value;
  48 {
  49     int written;
  50     FILE *fpin, *fpout;
  51     char varfile[128], varfilebackup[128], varbfr[512];
  52
  53     written = 0;
  54
  55     if (get_localvarfile(varfile))
  56         return (ZERR_INTERNAL);
  57
  58     (void) strcpy(varfilebackup, varfile);
  59     (void) strcat(varfilebackup, ".backup");
  60
  61     if (!(fpout = fopen(varfilebackup, "w")))
  62         return (errno);
  63     if ((fpin = fopen(varfile, "r")) != NULL) {
  64         while (fgets(varbfr, sizeof varbfr, fpin) != (char *) 0) {
  65             if (varbfr[strlen(varbfr)-1] < ' ')
  66                 varbfr[strlen(varbfr)-1] = '\0';
  67             if (varline(varbfr, var)) {
  68                 fprintf(fpout, "%s = %s\n", var, value);
  69                 written = 1;
  70             }
  71             else
  72                 fprintf(fpout, "%s\n", varbfr);
  73         }
  74         (void) fclose(fpin);            /* don't care about errs on input */
  75     }
  76     if (!written)
  77         fprintf(fpout, "%s = %s\n", var, value);
  78     if (fclose(fpout) == EOF)
  79             return(EIO);                /* can't rely on errno */
  80     if (rename(varfilebackup, varfile))
  81         return (errno);
  82     return (ZERR_NONE);
  83 }
  84
  85 Code_t ZUnsetVariable(var)
  86     char *var;
  87 {
  88     FILE *fpin, *fpout;
  89     char varfile[128], varfilebackup[128], varbfr[512];
  90
  91     if (get_localvarfile(varfile))
  92         return (ZERR_INTERNAL);
  93
  94     (void) strcpy(varfilebackup, varfile);
  95     (void) strcat(varfilebackup, ".backup");
  96
  97     if (!(fpout = fopen(varfilebackup, "w")))
  98         return (errno);
  99     if ((fpin = fopen(varfile, "r")) != NULL) {
 100         while (fgets(varbfr, sizeof varbfr, fpin) != (char *) 0) {
 101             if (varbfr[strlen(varbfr)-1] < ' ')
 102                 varbfr[strlen(varbfr)-1] = '\0';
 103             if (!varline(varbfr, var))
 104                 fprintf(fpout, "%s\n", varbfr);
 105         }
 106         (void) fclose(fpin);            /* don't care about read close errs */
 107     }
 108     if (fclose(fpout) == EOF)
 109             return(EIO);                /* errno isn't reliable */
 110     if (rename(varfilebackup, varfile))
 111         return (errno);
 112     return (ZERR_NONE);
 113 }
 114
 115 static int get_localvarfile(bfr)
 116     char *bfr;
 117 {
 118     char *envptr;
 119     struct passwd *pwd;
 120
 121     envptr = getenv("HOME");
 122     if (envptr)
 123         (void) strcpy(bfr, envptr);
 124     else {
 125         if (!(pwd = getpwuid((int) getuid()))) {
 126             fprintf(stderr, "Zephyr internal failure: Can't find your entry in /etc/passwd\n");
 127             return (1);
 128         }
 129         (void) strcpy(bfr, pwd->pw_dir);
 130     }
 131
 132     (void) strcat(bfr, "/");
 133     (void) strcat(bfr, ".zephyr.vars");
 134     return (0);
 135 }
 136
 137 static char *get_varval(fn, var)
 138     char *fn;
 139     char *var;
 140 {
 141     FILE *fp;
 142     static char varbfr[512];
 143     int i;
 144
 145     fp = fopen(fn, "r");
 146     if (!fp)
 147         return ((char *)0);
 148
 149     while (fgets(varbfr, sizeof varbfr, fp) != (char *) 0) {
 150         if (varbfr[strlen(varbfr)-1] < ' ')
 151             varbfr[strlen(varbfr)-1] = '\0';
 152         if (!(i = varline(varbfr, var)))
 153             continue;
 154         (void) fclose(fp);              /* open read-only, don't care */
 155         return (varbfr+i);
 156     }
 157     (void) fclose(fp);                  /* open read-only, don't care */
 158     return ((char *)0);
 159 }
 160
 161 /* If the variable in the line bfr[] is the same as var, return index to
 162    the variable value, else return 0. */
 163 static int varline(bfr, var)
 164     char *bfr;
 165     char *var;
 166 {
 167     register char *cp;
 168
 169
 170     if (!bfr[0] || bfr[0] == '#')       /* comment or null line */
 171         return (0);
 172
 173     cp = bfr;
 174     while (*cp && !isspace(*cp) && (*cp != '='))
 175         cp++;
 176
 177 #define max(a,b) ((a > b) ? (a) : (b))
 178
 179     if (strncasecmp(bfr, var, max(strlen(var),cp - bfr)))
 180         return(0);                      /* var is not the var in
 181                                            bfr ==> no match */
 182
 183     cp = strchr(bfr, '=');
 184     if (!cp)
 185         return(0);
 186     cp++;
 187     while (*cp && isspace(*cp))         /* space up to variable value */
 188         cp++;
 189
 190     return (cp - bfr);                  /* return index */
 191 }