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