Set "Date Added" in macOS Finder to match "Date Modified"

date_add_to_mod.c

#include <stdlib.h>
#include <string.h>
#include <sys/attr.h>
#include <unistd.h>
#include <stdio.h>

/*
 * For a list of files set "Date Added" in
 * macOS Finder to match "Date Modified"
 *
 * Usage:
 * gcc -o date_add_to_mod date_add_to_mod.c
 * ./date_add_to_mod file1 file2 ...
 *
 * Based on code by andrew:
 * https://apple.stackexchange.com/a/446258/10074
 *
 * Further information:
 * https://keith.github.io/xcode-man-pages/getattrlist.2.html
 * https://keith.github.io/xcode-man-pages/setattrlist.2.html
 */

/*
 * Get kMDItemDateAdded of path.
 *
 * Returns:
 *   • 0 on success
 *   • 1 if a system call failed: check errno
 *   • 2 if something else went wrong
 */
int get_date_modified(const char* path, struct timespec * out) {

    attrgroup_t request_attrs = ATTR_CMN_RETURNED_ATTRS | ATTR_CMN_MODTIME;

    struct attrlist request;
    memset(&request, 0, sizeof(request));
    request.bitmapcount = ATTR_BIT_MAP_COUNT;
    request.commonattr = request_attrs;

    typedef struct {
        u_int32_t length;
        attribute_set_t returned;
        struct timespec modified;
    } __attribute__((aligned(4), packed)) response_buf_t;

    response_buf_t response;

    int err = getattrlist(path, &request, &response, sizeof(response), 0);
    if (err != 0) {
        return 1;
    }
    if (response.length != sizeof(response)) {
        // Need a different-sized buffer; but provided one of exactly required
        // size?!
        return 2;
    }
    if (response.returned.commonattr != request_attrs) {
        // Didn’t get back all requested common attributes
        return 2;
    }

    out->tv_sec = response.modified.tv_sec;
    out->tv_nsec = response.modified.tv_nsec;

    return 0;
}

/*
 * Set kMDItemDateAdded of path.
 *
 * Returns:
 *   • 0 on success
 *   • 1 if a system call failed: check errno
 */
int set_date_added(const char* path, struct timespec in) {
    attrgroup_t request_attrs = ATTR_CMN_ADDEDTIME;

    struct attrlist request;
    memset(&request, 0, sizeof(request));
    request.bitmapcount = ATTR_BIT_MAP_COUNT;
    request.commonattr = request_attrs;

    typedef struct {
        struct timespec added;
    } __attribute__((aligned(4), packed)) request_buf_t;

    request_buf_t request_buf;
    request_buf.added.tv_sec = in.tv_sec;
    request_buf.added.tv_nsec = in.tv_nsec;

    int err = setattrlist(path, &request, &request_buf, sizeof(request_buf), 0);
    if (err != 0) {
        return 1;
    }

    return 0;
}

/*
 * Set kMDItemDateAdded of path to kMDItemFSContentChangeDate
 *
 * Returns:
 *   • 0 on success
 *   • 1 if a path doesn't exist
 *   • 2 if a function call failed
 */
int date_added_to_modifed(char* path) {
    
    int err;
    
    if(access(path, F_OK) != 0) {
        printf("error: %s doesn't exist\n", path);
        return 1;
    } 
    
    struct timespec out;
    err = get_date_modified(path, &out);
    if (err != 0) {
        return 2;
    }

    struct timespec in;
    in.tv_sec = out.tv_sec;
    in.tv_nsec = out.tv_nsec;
    err = set_date_added(path, in);
    if (err != 0) {
        return 2;
    }
    
    return 0;
}


/*
 * Modify paths given as command line arguments
 *
 * Returns:
 *   • 0 on success
 *   • 1 if a path doesn't exist
 *   • 2 if something else went wrong
 */
int main(int argc, char **argv) {
    
    if (argc >= 2) {
        for (int i = 1; i < argc; ++i) {
            char *path = argv[i];
            int err = date_added_to_modifed(path);
            if (err == 0) {
                printf("%s\n", path);
            }
            else if (err == 2) {
                printf("an unknown error occured\n");
                return 2;
            }
        }
    }
    else {
        printf("usage: date_add_to_mod file1 file2 ...\n");
    }

    return EXIT_SUCCESS;
}

Thank you! I think I've used this as a reference.

For packaged tool that does this and more, see https://github.com/Bobronium/mactime

Wow, thanks for packaging this (and more) up! I really like the output format flexibility. The Finder format looks nice and is great to compare the attributes of multiple files, but to compare the attributes of one file and for 80 character terminals the YAML format works better :)