platform_system_core/adb/utils.c

107 lines
2.5 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "utils.h"
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
char*
buff_addc (char* buff, char* buffEnd, int c)
{
int avail = buffEnd - buff;
if (avail <= 0) /* already in overflow mode */
return buff;
if (avail == 1) { /* overflowing, the last byte is reserved for zero */
buff[0] = 0;
return buff + 1;
}
buff[0] = (char) c; /* add char and terminating zero */
buff[1] = 0;
return buff + 1;
}
char*
buff_adds (char* buff, char* buffEnd, const char* s)
{
int slen = strlen(s);
return buff_addb(buff, buffEnd, s, slen);
}
char*
buff_addb (char* buff, char* buffEnd, const void* data, int len)
{
int avail = (buffEnd - buff);
if (avail <= 0 || len <= 0) /* already overflowing */
return buff;
if (len > avail)
len = avail;
memcpy(buff, data, len);
buff += len;
/* ensure there is a terminating zero */
if (buff >= buffEnd) { /* overflow */
buff[-1] = 0;
} else
buff[0] = 0;
return buff;
}
char*
buff_add (char* buff, char* buffEnd, const char* format, ... )
{
int avail;
avail = (buffEnd - buff);
if (avail > 0) {
va_list args;
int nn;
va_start(args, format);
nn = vsnprintf( buff, avail, format, args);
va_end(args);
if (nn < 0) {
/* some C libraries return -1 in case of overflow,
* but they will also do that if the format spec is
* invalid. We assume ADB is not buggy enough to
* trigger that last case. */
nn = avail;
}
else if (nn > avail) {
nn = avail;
}
buff += nn;
/* ensure that there is a terminating zero */
if (buff >= buffEnd)
buff[-1] = 0;
else
buff[0] = 0;
}
return buff;
}