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

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