Post by jakPost by firPost by jakPost by firPost by firi want to save bitmap (when using editor) but i dont wannt
to pen a dialog for saving ui just wana do quicksave but not replace
the file already exist so i want to maybe use such scheme i will sawe
"painting001.bmp" and if there is such number i will just increase
the number to 002 if such exist i will use 003 and so on
do yu thing it is standable to use c std lib (and probably just
fopen fclose to detect if that file already exist of there is a need
to use some specific windows functions?
i never used it though - though maybe i could becouse code
that is able to walk on directories and read all files may be handy
for various practical usage (liek finding something , removing
duplicates etc)
the question is if if somoene would work longer and had 1000 bitmaps
in folder if this will not slow down, or still be fast etc...could check
experimentally but even then i wouldnt be sure if this is kinda
optimal or wastefull way
In order not to manage too many differences between compilers you could
#include <stdio.h>
#include <limits.h>
int main()
{
    char pref[50] = "bmp_file_",
         cmd[1024],
         str[PATH_MAX];
    int seq;
    FILE *fp, *f;
    sprintf(cmd, "c:\\windows\\system32\\cmd.exe /c dir /b /o:-n %s???
2>nul", pref);
    if((fp = popen(cmd, "rt")) != NULL)
    {
        if(fgets(str, PATH_MAX, fp) != NULL)
        {
            sscanf(str, "%[^0-9]%3d%*", pref, &seq);
            sprintf(str, "%s%03d", pref, ++seq);
        }
        else
            sprintf(str, "%s%03d", pref, 1);
        pclose(fp);
        if((f = fopen(str, "r")) == NULL)
        {
            if((f = fopen(str, "w")) == NULL)
                printf("cannot create %s", str);
        }
        else
            printf("%s already exist", str);
        if(f != NULL) fclose(f);
    }
    else
        printf("cannot open process");
    return 0;
}
This piece of code is only used to give the idea and is not well tested.
that is almost for sure bad - its liek running separate console program
to add two strings or numbers
I knew you would have given a similar answer but if you agree to open
thousands of files to find the last of them, then you could accept that
solution. It does not only do what you say because the system call is
looking for the file for patterns and reverses the order of the list.
All things you should do in your program. In any case, on Windows
systems there are FindFirst/FindNext functions for this type of
operations. Below is an example where I replace the system call with a
function that uses the functions given before. The convenience of the
system call is that on systems *nix works by simply replacing the call
with "/usr/bin/ls -1r .......".
#include <stdio.h>
#include <limits.h>
#include <stdbool.h>
#include <windows.h>
bool FindLastOf(char [], char *);
int main()
{
char pref[] = "bmp_file_",
f2find[50],
str[PATH_MAX];
int seq;
FILE *f;
sprintf(f2find, "%s????", pref);
if(FindLastOf(f2find, str))
{
sscanf(str, "%[^0-9]%4d%*", pref, &seq);
sprintf(str, "%s%04d", pref, ++seq);
}
else
sprintf(str, "%s%04d", pref, 1);
if((f = fopen(str, "r")) == NULL)
{
if((f = fopen(str, "w")) == NULL)
printf("cannot create %s", str);
}
else
printf("%s already exist", str);
if(f != NULL) fclose(f);
return 0;
}
bool FindLastOf(char what[], char *result)
{
WIN32_FIND_DATA fdF;
HANDLE hF= NULL;
bool ret = false;
*result = '\0';
if((hF = FindFirstFile(what, &fdF)) != INVALID_HANDLE_VALUE)
{
do
if(strcmp(fdF.cFileName, result) > 0)
strcpy(result, fdF.cFileName);
while(FindNextFile(hF, &fdF));
ret = true;
FindClose(hF);
}
return ret;
}
Not even this piece of code is well tested and is just an example.
Unfortunately, on the systems where the opendir/readir functions are
available instead of FindFirst/FindFext, the work will be more difficult
because they do not have the receipt for patterns.