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
21char*
22buff_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
39char*
40buff_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
47char*
48buff_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
71char*
72buff_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