appendattr.cpp

#include <Node.h>
#include <TypeConstants.h>

#include <fs_attr.h>

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


int
main(int argc, char *argv[])
{
    if (argc < 3) {
        printf("usage: %s <fileName> <attributeName> <valueToAppend>\n",
            argv[0]);
        exit(1);
    }

    const char *fileName = argv[1];
    const char *attrName = argv[2];
    const char *value = argv[3];

    BNode node(fileName);
    status_t result = node.InitCheck();
    if (result != B_OK) {
        printf("failed to open node \"%s\": %s\n", fileName, strerror(result));
        exit(2);
    }

    attr_info attrInfo;
    result = node.GetAttrInfo(attrName, &attrInfo);
    if (result == B_ENTRY_NOT_FOUND) {
        // No attribute yet, pretend it's there but has length 0
        attrInfo.type = B_STRING_TYPE;
        attrInfo.size = 0;
    } else if (result != B_OK) {
        printf("failed to get info for attribute \"%s\": %s\n", attrName,
            strerror(result));
        exit(3);
    }

    if (attrInfo.type != B_STRING_TYPE) {
        printf("attribute \"%s\" isn't a string, aborting\n", attrName);
        exit(4);
    }

    ssize_t written = node.WriteAttr(attrName, attrInfo.type, attrInfo.size,
        value, strlen(value));
    if (written < 0) {
        printf("failed to append to attribute: %s\n", strerror(written));
        exit(5);
    }

    printf("appended %" B_PRIdSSIZE " bytes to to attribute \"%s\" of \"%s\"\n",
        written, attrName, fileName);
    exit(0);
}