Home | History | Annotate | Download | only in adb 
      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 #include "utils.h"
     17 #include <stdarg.h>
     18 #include <stdio.h>
     19 #include <string.h>
     20 
     21 char*
     22 buff_addc (char*  buff, char*  buffEnd, int  c)
     23 {
     24     int  avail = buffEnd - buff;
     25 
     26     if (avail <= 0)  /* already in overflow mode */
     27         return buff;
     28 
     29     if (avail == 1) {  /* overflowing, the last byte is reserved for zero */
     30         buff[0] = 0;
     31         return buff + 1;
     32     }
     33 
     34     buff[0] = (char) c;  /* add char and terminating zero */
     35     buff[1] = 0;
     36     return buff + 1;
     37 }
     38 
     39 char*
     40 buff_adds (char*  buff, char*  buffEnd, const char*  s)
     41 {
     42     int  slen = strlen(s);
     43 
     44     return buff_addb(buff, buffEnd, s, slen);
     45 }
     46 
     47 char*
     48 buff_addb (char*  buff, char*  buffEnd, const void*  data, int  len)
     49 {
     50     int  avail = (buffEnd - buff);
     51 
     52     if (avail <= 0 || len <= 0)  /* already overflowing */
     53         return buff;
     54 
     55     if (len > avail)
     56         len = avail;
     57 
     58     memcpy(buff, data, len);
     59 
     60     buff += len;
     61 
     62     /* ensure there is a terminating zero */
     63     if (buff >= buffEnd) {  /* overflow */
     64         buff[-1] = 0;
     65     } else
     66         buff[0] = 0;
     67 
     68     return buff;
     69 }
     70 
     71 char*
     72 buff_add  (char*  buff, char*  buffEnd, const char*  format, ... )
     73 {
     74     int      avail;
     75 
     76     avail = (buffEnd - buff);
     77 
     78     if (avail > 0) {
     79         va_list  args;
     80         int      nn;
     81 
     82         va_start(args, format);
     83         nn = vsnprintf( buff, avail, format, args);
     84         va_end(args);
     85 
     86         if (nn < 0) {
     87             /* some C libraries return -1 in case of overflow,
     88              * but they will also do that if the format spec is
     89              * invalid. We assume ADB is not buggy enough to
     90              * trigger that last case. */
     91             nn = avail;
     92         }
     93         else if (nn > avail) {
     94             nn = avail;
     95         }
     96 
     97         buff += nn;
     98 
     99         /* ensure that there is a terminating zero */
    100         if (buff >= buffEnd)
    101             buff[-1] = 0;
    102         else
    103             buff[0] = 0;
    104     }
    105     return buff;
    106 }
    107