diplodocus.org Git - nmh/blob - sbr/utils.c

   1
   2 /*
   3  * utils.c -- various utility routines
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2006, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13 #include <h/utils.h>
  14 #include <stdlib.h>
  15 #include <fcntl.h>
  16 #include <errno.h>
  17
  18 /*
  19  * We allocate space for messages (msgs array)
  20  * this number of elements at a time.
  21  */
  22 #define MAXMSGS 256
  23
  24 /*
  25  * Safely call malloc
  26  */
  27 void *
  28 mh_xmalloc(size_t size)
  29 {
  30     void *memory;
  31
  32     if (size == 0)
  33         adios(NULL, "Tried to malloc 0 bytes");
  34
  35     memory = malloc(size);
  36     if (!memory)
  37         adios(NULL, "Malloc failed");
  38
  39     return memory;
  40 }
  41
  42 /*
  43  * Safely call realloc
  44  */
  45 void *
  46 mh_xrealloc(void *ptr, size_t size)
  47 {
  48     void *memory;
  49
  50     /* Some non-POSIX realloc()s don't cope with realloc(NULL,sz) */
  51     if (!ptr)
  52         return mh_xmalloc(size);
  53
  54     if (size == 0)
  55         adios(NULL, "Tried to realloc 0bytes");
  56
  57     memory = realloc(ptr, size);
  58     if (!memory)
  59         adios(NULL, "Realloc failed");
  60
  61     return memory;
  62 }
  63
  64 /*
  65  * Return the present working directory, if the current directory does not
  66  * exist, or is too long, make / the pwd.
  67  */
  68 char *
  69 pwd(void)
  70 {
  71     register char *cp;
  72     static char curwd[PATH_MAX];
  73
  74     if (!getcwd (curwd, PATH_MAX)) {
  75         admonish (NULL, "unable to determine working directory");
  76         if (!mypath || !*mypath
  77                 || (strcpy (curwd, mypath), chdir (curwd)) == -1) {
  78             strcpy (curwd, "/");
  79             chdir (curwd);
  80         }
  81         return curwd;
  82     }
  83
  84     if ((cp = curwd + strlen (curwd) - 1) > curwd && *cp == '/')
  85         *cp = '\0';
  86
  87     return curwd;
  88 }
  89
  90 /*
  91  * add   -- If "s1" is NULL, this routine just creates a
  92  *       -- copy of "s2" into newly malloc'ed memory.
  93  *       --
  94  *       -- If "s1" is not NULL, then copy the concatenation
  95  *       -- of "s1" and "s2" (note the order) into newly
  96  *       -- malloc'ed memory.  Then free "s1".
  97  */
  98 char *
  99 add (char *s2, char *s1)
 100 {
 101     char *cp;
 102     size_t len1 = 0, len2 = 0;
 103
 104     if (s1)
 105         len1 = strlen (s1);
 106     if (s2)
 107         len2 = strlen (s2);
 108
 109     cp = mh_xmalloc (len1 + len2 + 1);
 110
 111     /* Copy s1 and free it */
 112     if (s1) {
 113         memcpy (cp, s1, len1);
 114         free (s1);
 115     }
 116
 117     /* Copy s2 */
 118     if (s2)
 119         memcpy (cp + len1, s2, len2);
 120
 121     /* Now NULL terminate the string */
 122     cp[len1 + len2] = '\0';
 123
 124     return cp;
 125 }
 126
 127 /*
 128  * folder_exists
 129  *      Check to see if a folder exists.
 130  */
 131 int folder_exists(char *folder)
 132 {
 133     struct stat st;
 134     int exists = 0;
 135
 136     if (stat (folder, &st) == -1) {
 137         /* The folder either doesn't exist, or we hit an error.  Either way
 138          * return a failure.
 139          */
 140         exists = 0;
 141     } else {
 142         /* We can see a folder with the right name */
 143         exists = 1;
 144     }
 145
 146     return exists;
 147 }
 148
 149
 150 /*
 151  * create_folder
 152  *      Check to see if a folder exists, if not, prompt the user to create
 153  *      it.
 154  */
 155 void create_folder(char *folder, int autocreate, void (*done_callback)(int))
 156 {
 157     struct stat st;
 158     extern int errno;
 159     char *cp;
 160
 161     if (stat (folder, &st) == -1) {
 162         if (errno != ENOENT)
 163             adios (folder, "error on folder");
 164         if (autocreate == 0) {
 165             /* ask before creating folder */
 166             cp = concat ("Create folder \"", folder, "\"? ", NULL);
 167             if (!getanswer (cp))
 168                 done_callback (1);
 169             free (cp);
 170         } else if (autocreate == -1) {
 171             /* do not create, so exit */
 172             done_callback (1);
 173         }
 174         if (!makedir (folder))
 175             adios (NULL, "unable to create folder %s", folder);
 176     }
 177 }
 178
 179 /*
 180  * num_digits
 181  *      Return the number of digits in a nonnegative integer.
 182  */
 183 int
 184 num_digits (int n)
 185 {
 186     int ndigits = 0;
 187
 188     /* Sanity check */
 189     if (n < 0)
 190         adios (NULL, "oops, num_digits called with negative value");
 191
 192     if (n == 0)
 193         return 1;
 194
 195     while (n) {
 196         n /= 10;
 197         ndigits++;
 198     }
 199
 200     return ndigits;
 201 }
 202
 203 /*
 204  * Append a message arg to an array of them, resizing it if necessary.
 205  * The function is written to suit the arg parsing code it was extracted
 206  * from, and will probably be changed when the other code is cleaned up.
 207  */
 208 void
 209 app_msgarg(struct msgs_array *msgs, char *cp)
 210 {
 211         if(msgs->size >= msgs->max)
 212                 msgs->msgs = mh_xrealloc(msgs->msgs, (msgs->max+=MAXMSGS)*sizeof(*msgs->msgs));
 213         msgs->msgs[msgs->size++] = cp;
 214 }
 215
 216 /* Open a form or components file */
 217 int
 218 open_form(char **form, char *def)
 219 {
 220         int in;
 221         if (*form) {
 222                 if ((in = open (etcpath (*form), O_RDONLY)) == NOTOK)
 223                         adios (*form, "unable to open form file");
 224         } else {
 225                 if ((in = open (etcpath (def), O_RDONLY)) == NOTOK)
 226                         adios (def, "unable to open default components file");
 227                 *form = def;
 228         }
 229         return in;
 230 }