UNIX for Advanced & Expert Users

#include <stdio.h>
#include <zip.h>
#include <errno.h>

int main(int argc, char *argv[])
{
        int n, err, index=-1;
        struct zip *z;

        if(argc != 4)
        {
                printf("syntax: %s file.zip oldname newname\n", argv[0]);
                return(1);
        }

        z=zip_open(argv[1], 0, &err);

        if(z == NULL)
        {
                char buf[512];
                zip_error_to_str(buf, 512, err, errno);
                fprintf(stderr, "Couldn't open zip: %s\n", buf);
        }

        for(n=0; n<zip_get_num_files(z); n++)
        {
                const char *name=zip_get_name(z, n, 0);
                if(strcmp(name, argv[2]) == 0)
                {
                        index=n;
                        break;
                }
        }
        if(index < 0)
        {
                fprintf(stderr, "Couldn't find %s\n", argv[2]);
                return(1);
        }

        fprintf(stderr, "Found %s at %d\n", argv[2], index);

        if(zip_rename(z, index, argv[3]) < 0)
        {
                fprintf(stderr, "Couldn't rename file\n");
                zip_close(z);
                return(1);
        }

        zip_close(z);
        return(0);
}