strdup assignment makes pointer from integer without a cast

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[SOLVED] C - assigment makes integer from pointer without a cast warning

Thread: [solved] c - assigment makes integer from pointer without a cast warning, thread tools.

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I know it's a common error, and I've tried googling it, looked at a bunch of answers, but I still don't really get what to do in this situation.... Here's the relevant code: Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main( int argc, char *argv[] ) { char path[51]; const char* home = getenv( "HOME" ); strcpy( path, argv[1] ); path[1] = home; return 0; } -- there is more code in the blank lines, but the issue's not there (I'm fairly sure), so didn't see the point in writing out 100 odd lines of code. I've tried some stuff like trying to make a pointer to path[1], and make that = home, but haven't managed to make that work (although maybe that's just me doing it wrong as opposed to wrong idea?) Thanks in advance for any help

Re: C - assigment makes integer from pointer without a cast warning

path[1] is the second element of a char array, so it's a char. home is a char *, i.e. a pointer to a char. You get the warning because you try to assign a char* to a char. Note also the potential to overflow your buffer if the content of the argv[1] argument is very long. It's usually better to use strncpy.

Last edited by r-senior; March 10th, 2013 at 03:03 PM . Reason: argv[1] would overflow, not HOME. Corrected to avoid confusion.

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You can try something like this: Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main( int argc, char *argv[] ) { char *path; const char *home = getenv("HOME"); path = malloc(strlen(home) + 1); if (!path) { printf("Error\n"); return 0; } strcpy(path, home); printf("path = %s\n", path); // if you want to have argv[1] concatenated with path if (argc >= 2) { path = malloc(strlen(home) + strlen(argv[1]) + 1); strcpy(path, argv[1]); strcat(path, home); printf("%s\n", path); } // if you want an array of strings, each containing path, argv[1]... char **array; int i; array = malloc(argc * sizeof(char*)); array[0] = malloc(strlen(home) + 1); strcpy(array[0], home); printf("array[0] = %s\n", array[0]); for (i = 1; i < argc; i++) { array[i] = malloc(strlen(argv[i]) + 1); strcpy(array[i], argv[i]); printf("array[%d] = %s\n", i, array[i]); } // now array[i] will hold path and all the argv strings return 0; } Just as above, your path[51] is a string while path[1] is only a character, so you can't use strcpy for that.

Last edited by Christmas; March 10th, 2013 at 09:51 PM .

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Originally Posted by Christmas You can try something like this: Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main( int argc, char *argv[] ) { char *path; const char *home = getenv("HOME"); path = malloc(strlen(home) + 1); if (!path) { printf("Error\n"); return 0; } strcpy(path, home); printf("path = %s\n", path); // if you want to have argv[1] concatenated with path if (argc >= 2) { path = malloc(strlen(home) + strlen(argv[1]) + 1); strcpy(path, argv[1]); strcat(path, home); printf("%s\n", path); } // if you want an array of strings, each containing path, argv[1]... char **array; int i; array = malloc(argc * sizeof(char*)); array[0] = malloc(strlen(home) + 1); strcpy(array[0], home); printf("array[0] = %s\n", array[0]); for (i = 1; i < argc; i++) { array[i] = malloc(strlen(argv[i]) + 1); strcpy(array[i], argv[i]); printf("array[%d] = %s\n", i, array[i]); } // now array[i] will hold path and all the argv strings return 0; } Just as above, your path[51] is a string while path[1] is only a character, so you can't use strcpy for that. Excellent point. I've basically fixed my problem by reading up on pointers again (haven't done any C for a little while, so forgot some stuff), and doing: Code: path[1] = *home; the code doesn't moan at me when I compile it, and it runs okay (for paths which aren't close to 51 at least), but after reading what you read, I just wrote a quick program and found out that getenv("HOME") is 10 characters long, not 1 like I seem to have assumed, so I'll modify my code to fix that.

Yes, getenv will return the path to your home dir, for example /home/user, but path[1] = *home will still assign the first character of home to path[1] (which would be '/').

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assignment makes pointer from integer without a cast

Errors when compiling. its seem to be complaining about line 52 and i do not get output of second file.(data.words) strarray[numStrings++]=strdup(word);

$ gcc -Wall -ansi prt.c -o prt In function ‘main’: warning: implicit declaration of function ‘strdup’ warning: assignment makes pointer from integer without a cast

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remove the -ansi flag and you won't get those warnings. The only reason I know of to use -ansi it to compile old lagecy code, written last century.

Where is strdup() defined? How is it defined? It's not an ANSI function.

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I already tried that, it works but I get seg fault. I am running on x86_64 x86_64 x86_64 GNU/Linux

kinda have to be executed with -ansi, per instructor. Any other ideas??

ahh! something I never expected. Thanks for the tip

strdup is part of the GNU C library which can be found basically every linux machine. It is a declared inside of string.h. It duplicates a string like strcpy, but uses malloc so it can be freed later.

I just tried to compile that code on Ubantu and got the same errors. If you look at /usr/include/string.h you will see that strdup() is conditionally defined

As Walt already said strdup() is not an ansi function. You will have to remove the -ansi flag from the command line options in order to use strdup(), or define one of the macros in the #if statement.

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C语言assignment makes pointer from integer without a cast

这个警告的意思是将一个int整数值直接赋值给了一个指针变量。（ 重点是类型不一致 ）

消除警告的方法就是明确类型转换是否是正确的，如果确实要把整数变量赋予指针变量，那么请使用强制类型转换。否则，请用相同的数据类型，这样编译器就不会显示警告。

比如： int *p = 10;   //这就会产生这个警告

                                //因为 p 是指针变量，存放的是地址。而10是一个整数常量

改成： int *p = (int *)10    //强制转换成同一类型就可以消除警告

                                        //强制类型转换，10强制转换成了一个地址

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passing argument 1 of 'strlen' makes pointer from integer without a cast

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I write code witch generate file name based on: destination directory settings, radio station presets list and current time. If users store radio station name (app presets) with white space in name: Europa FM Paprika Radio Radio France Internationale ........................... Rock FM I want to remove whitespace for recording radio station filename and result look like this: /home/ubuntu/Desktop/EuropaFM_07042012-111705.ogg Code: static int start_recording(const gchar *destination, const char* station, const char* time) {     Recording* recording;     char *filename;     char* remove_whitespace(station)     {         char* result = malloc(strlen(station)+1);         char* i;         int temp = 0;         for( i = station; *i; ++i)             if(*i != ' ')             {                 result[temp] = (*i);                 ++temp;             }         result[temp] = '\0';         return result;     }     filename = g_strdup_printf(_("%s/%s_%s"),         destination,         remove_whitespace(station),         time);     recording = recording_start(filename);     g_free(filename);     if (!recording)         return -1;     recording->station = g_strdup(station);     tray_icon_items_set_sensible(FALSE);     record_status_window(recording);     run_status_window(recording);     return 1; } But this get warnings: warning: passing argument 1 of 'strlen' makes pointer from integer without a cast [enabled by default] warning: assignment makes pointer from integer without a cast [enabled by default] I appreciate your help. Thanks.

O_o Missing ';' can cause unusual problems... Soma

Please explain the following snippet: Code: char* remove_whitespace(station)     {         char* result = malloc(strlen(station)+1);         char* i;         int temp = 0;         for( i = station; *i; ++i)             if(*i != ' ')             {                 result[temp] = (*i);                 ++temp;             }         result[temp] = '\0';         return result;     } To me this looks like a function implementation. inside another function, using a default integer parameter. Which should explain the error message. Several problems, one never implement a function inside a function. Two never use default parameters when defining, implementing functions. Three you probably have a memory leak because you aren't assigning the value being returned to any variable. Jim

Quote: Originally Posted by jimblumberg Please explain the following snippet: Code: char* remove_whitespace(station)     {         char* result = malloc(strlen(station)+1);         char* i;         int temp = 0;         for( i = station; *i; ++i)             if(*i != ' ')             {                 result[temp] = (*i);                 ++temp;             }         result[temp] = '\0';         return result;     } To me this looks like a function implementation. inside another function, using a default integer parameter. Which should explain the error message. Several problems, one never implement a function inside a function. Two never use default parameters when defining, implementing functions. Three you probably have a memory leak because you aren't assigning the value being returned to any variable. Jim Maybe solution is to remove whitespace here? Code: void rec_button_clicked_cb(GtkButton *button, gpointer app) {     char *station;     char time_str[100];     time_t t;         t = time(NULL);     /* consult man strftime to translate this. This is a filename, so don't use "/" or ":", please */     strftime(time_str, 100, _("%m%d%Y-%H%M%S"), localtime(&t));         if (mom_ps < 0) {         station = g_strdup_printf(_("%.2f MHz"), rint(gtk_adjustment_get_value(adj))/STEPS);     } else {         g_assert(mom_ps < g_list_length(settings.presets));         preset* ps = g_list_nth_data(settings.presets, mom_ps);         g_assert(ps);             station = g_strdup(ps->title);     }

Quote: Maybe solution is to remove whitespace here? I don't know, maybe here, maybe there. That is a decision you need to make. I didn't see anything wrong about where you were trying to remove the whitespace in your original post, just the method used. As to where you remove the whitespace, that is a design decision that you the programmer must make. Jim

Because you have not specified the type of parameter station in the remove_whitespace function declaration, it defaults to an int . I'd recommend using a simple file name sanitizer instead, which also prepends the specified directory name (NULL if none) to yield the full path to the target file. Code: #include <stdlib.h> #include <string.h> #include <errno.h> static inline char *path_to(const char *const dir, const char *const name) {     const size_t  dirlen = (dir) ? strlen(dir) : 0;     const size_t  namelen = (name) ? strlen(name) : 0;     char        *result;     const unsigned char *s;     unsigned char *d;     /* Empty name is not allowed. */     if (namelen < 1) {         errno = EINVAL;         return NULL;     }     result = malloc(dirlen + namelen + 4);     if (!result) {         errno = ENOMEM;         return NULL;     }     d = (unsigned char *)result;     if (namelen > 0) {         s = (const unsigned char *)dir;         if (*s != '/')             *(d++) = '.';         while (1) {             while (*s == '/')                 s++;             if (!*s)                 break;             *(d++) = '/';             while (*s && *s != '/')                 *(d++) = *(s++);         }       *(d++) = '/';     }     s = (const unsigned char *)name;     while (*s)         if (*s <= 32 || *s == 47 || *s == 127)             s++; /* Skip whitespace, control chars, and slashes */         else             *(d++) = *(s++);     /* Terminate path. */     *d = '\0';     /* Empty result? */     if ((char *)d == result) {         free(result);         errno = EINVAL;         return NULL;     }     /* Empty file name part? */     if (*(d - 1) == '/') {         free(result);         errno = EINVAL;         return NULL;     }     return result; } The above one does not sanitize the directory part, only the file name part. ASCII control characters, ASCII whitespace, and slashes (/) are removed from the file name part. If a path can be constructed safely, it is returned as a dynamically allocated string. After you no longer need it, you must remember to free() the returned pointer. If the function cannot construct a path to a file, it will return NULL, with errno set to indicate the reason: ENOMEM if out of memory, and EINVAL if the file name part is empty. It is safe to call the function with NULL parameters. The directory may be NULL; the path generated will then have no directory part. (If the directory part is empty, the result will start with ./ , i.e. current directory). The file name part must not be empty, or be empty after sanitization, or the function will return NULL with errno set to EINVAL. In your particular case, I'd use Code: /* Instead of 'time' to the function, pass a pointer to GDateTime: */ GDateTime *now; g_char *temptime, *tempname; char *path; temptime = g_date_time_format(_("%x %X"), now); if (!temptime)     return 0; /* Out of memory, or localization error */ tempname = g_strdup_printf(_("%1$s_%2$s"), station, temptime); g_free(temptime); if (!tempname)     return 0; /* Out of memory, or localization error */ path = path_to((const char *)destination, (const char *)tempname); if (!path) {     /* errno == EINVAL: Invalid file name (possibly bad localization),     * errno == ENOMEM: Out of memory.     */     g_free(tempname);     return 0; /* Out of memory, invalid file name, or localization error */ } g_free(tempname); /* Record to file 'path' ... */ free(path); return 1; /* Success */ This way the way time is used in the file names is localizable. It should default to full date and time according to the current locale. Also, the way the station name and date-time is combined to form the file name is localizable. Whatever we get after the two localization steps, we feed through the function I showed above, to construct the full path to the target file. For example, if I localized that to Finnish, I'd use YYYYMMDD-hhmm- station by using %Y%m%d-%H%M and %2$s-%1$s in the .po file. Note how the above calls g_free() and free() to discard the dynamically allocated temporaries when they're no longer used. It will not leak memory even if an error occurs. (For future reference: It is very useful to remember that both g_free(NULL) and free(NULL) are safe; they do nothing. If you start getting complicated if clauses at the error conditions, just initialize all dynamically allocated temporaries to NULL, and in all exit cases just free them all unconditionally. Elsewhere, when you free something, also assign the pointer to NULL. It is safe, and yields quite readable code, although some programmers complain about how the "superfluous" free()s and g_free()s hurt their eyes or something.)

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The routine below draws an image on a tft-screen, and although the whole programm works fine and the image is displayed ok, I'm unable to resolve this 'assignment' warning at pS=pS0+n; .

I've tried several casts, but as yet not the right one (I'm not so well versed in casting).

Can anyone help with the solution?

Definition of the image:

Drawing the image:

The actual routine:

pS0 should have the same type as pS (const char *), and definitely not unsigned int.

TNKernel-PIC32, an open-source real-time kernel for the PIC32

I don't understand why you have ps0 defined as...

If you define it as the correct type, you can avoid all the ugly and unecessary casting:

Edit: andersm beat me to it.

It also seems a lot of your variables are incorrectly sized.  rgb8 could easily be unsigned char, for example.

You are trying to convert an pointer to an integer without cast and it is simply telling you that the correct type is what pS type is that is the thing that line is trying to set after all

That all said it would be a hell of a lot easier to make PS0 a const char* and simply tell it

Thank you all for the replies. I think this will help me resolve it. And the the other tips too!

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