dav/xattrtool.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2019 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * small tool for accessing extended attributes
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "libxattr.h"

int attrtool_list(int argc, char **argv, int values);
int attrtool_get(int argc, char **argv, int raw);
int attrtool_set(int argc, char **argv);
int attrtool_rm(int argc, char **argv);

void print_usage(char *cmd) {
    fprintf(stderr, "usage %s:\n", cmd);
    fprintf(stderr, "   list <file>\n");
    fprintf(stderr, "   listvalues <file>\n");
    fprintf(stderr, "   get <file> <name>\n");
    fprintf(stderr, "   set <file> <name> <value>\n");
    fprintf(stderr, "   remove <file> <name>\n");
}

int main(int argc, char **argv) {
    if(argc < 3) {
        print_usage(argv[0]);
        return 1;
    }
    
    if(!strcmp(argv[1], "list") || !strcmp(argv[1], "ls")) {
        return attrtool_list(argc, argv, 0);
    } else if(!strcmp(argv[1], "listvalues") || !strcmp(argv[1], "lsv")) {
        return attrtool_list(argc, argv, 1);
    } else if(!strcmp(argv[1], "get")) {
        return attrtool_get(argc, argv, 0);
    } else if(!strcmp(argv[1], "set")) {
        return attrtool_set(argc, argv);
    } else if(!strcmp(argv[1], "rm") || !strcmp(argv[1], "remove")) {
        return attrtool_rm(argc, argv);
    } else {
        fprintf(stderr, "Unknown command\n");
        print_usage(argv[0]);
    }
    
    return 1;
}

int attrtool_list(int argc, char **argv, int values) {
    ssize_t nelm = 0;
    char **list = xattr_list(argv[2], &nelm);
    if(nelm < 0) {
        perror("xattr_list");
        return 3;
    }
    
    for(int i=0;i<nelm;i++) {
        char *attr = list[i];
        if(values) {
            ssize_t valuelen = 0;
            char *value = xattr_get(argv[2], attr, &valuelen);
            if(valuelen < 0) {
                printf("%s: #ERROR: %s\n", attr, strerror(errno));
            } else {
                printf("%s: %.*s\n", attr, (int)valuelen, value);
            }
            
            if(value) {
                free(value);
            }
        } else {
            printf("%s\n", attr);
        }
        
        free(list[i]);
    }
    if(list) {
        free(list);
    }
    
    return 0;
}

int attrtool_get(int argc, char **argv, int raw) {
    if(argc < 4) {
        fprintf(stderr, "Too few arguments\n");
        print_usage(argv[1]);
        return 1;
    }
    
    char *file = argv[2];
    char *attr = argv[3];
    int ret = 0;
    
    size_t valuelen = 0;
    char *value = xattr_get(file, attr, &valuelen);
    if(value) {
        if(raw) {
            fwrite(value, 1, valuelen, stdout);
        } else {
            printf("%.*s\n", (int)valuelen, value);
        }
        free(value);
    } else {
        perror("xattr_get");
        ret = 3;
    }
    
    return ret;
}

int attrtool_set(int argc, char **argv) {
    if(argc < 4) {
        fprintf(stderr, "Too few arguments\n");
        print_usage(argv[1]);
        return 1;
    }
    
    size_t len = strlen(argv[4]);
    char *file = argv[2];
    char *attr = argv[3];
    char *value = argv[4];
    int ret = 0;
    
    if(xattr_set(file, attr, value, len)) {
        perror("xattr_set");
        ret = 3;
    }
    
    return ret;
}

int attrtool_rm(int argc, char **argv) {
    if(argc < 4) {
        fprintf(stderr, "Too few arguments\n");
        print_usage(argv[1]);
        return 1;
    }
    
    char *file = argv[2];
    char *attr = argv[3];
    int ret = 0;
    
    if(xattr_remove(file, attr)) {
        perror("xattr_remove");
        ret = 1;
    }
    
    return ret;
}