nuttx-apps/system/hostname/hostname_main.c

154 lines
4.5 KiB
C

/****************************************************************************
* apps/system/hostname/hostname_main.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: show_usage
****************************************************************************/
static void show_usage(FAR const char *progname)
{
printf("Usage: %s [<hostname>|-F <file>]\n", progname);
}
/****************************************************************************
* Public Functions
****************************************************************************/
int main(int argc, FAR char *argv[])
{
int ret;
bool set = false;
FAR FILE *f;
char hostname[HOST_NAME_MAX + 2];
while ((ret = getopt(argc, argv, ":F:h")) != ERROR)
{
switch (ret)
{
case 'F':
set = true;
f = fopen(optarg, "r");
if (f == NULL)
{
fprintf(stderr, "ERROR: Failed to open '%s': %s\n", optarg,
strerror(errno));
return EXIT_FAILURE;
}
if (fgets(hostname, sizeof(hostname), f) == NULL)
{
if (errno != 0)
{
fprintf(stderr, "ERROR: Failed to read '%s': %s\n",
optarg, strerror(errno));
fclose(f);
return EXIT_FAILURE;
}
hostname[0] = '\0';
}
else
{
*strchrnul(hostname, '\n') = '\0';
}
fclose(f);
break;
case 'h':
show_usage(argv[0]);
return EXIT_SUCCESS;
case ':':
fprintf(stderr, "ERROR: Option needs a value: '%c'\n", optopt);
show_usage(argv[0]);
return EXIT_FAILURE;
default:
case '?':
fprintf(stderr, "ERROR: Unrecognized option: '%c'\n", optopt);
show_usage(argv[0]);
return EXIT_FAILURE;
}
}
if (optind < argc && !set)
{
set = true;
strlcpy(hostname, argv[optind++], sizeof(hostname));
}
if (optind < argc)
{
fprintf(stderr, "ERROR: Too many arguments\n");
return -1;
}
if (set)
{
if (strlen(hostname) == 0 || strlen(hostname) > HOST_NAME_MAX)
{
fprintf(stderr, "ERROR: The specified hostname is invalid\n");
return EXIT_FAILURE;
}
ret = sethostname(hostname, strlen(hostname));
if (ret != 0)
{
fprintf(stderr, "sethostname() returned %d\n", ret);
return EXIT_FAILURE;
}
}
else
{
ret = gethostname(hostname, HOST_NAME_MAX);
if (ret != 0)
{
fprintf(stderr, "gethostname() returned %d\n", ret);
return EXIT_FAILURE;
}
printf("%s\n", hostname);
}
return EXIT_SUCCESS;
}