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POhow can i use output from sprintf as the filename for fopen?
 

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  1. POhow can i use output from sprintf as the filename for fopen?
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    <p>I am working on a log parsing program that retrieves the file to open by combining an environment variable and a preset string in order to provide the full path to the file, but i am having trouble getting fopen to take out the output from sprintf which i am using to combine the environment variable and the preset string,so i was wondering if anyone could offer advice on what i should do to get this to work properly? thanks! (i have just begun teaching myself C over the last few weeks, so im open to any tips no matter how obvious they should be to me)</p> <pre><code>#include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;string.h&gt; #define _GNU_SOURCE void main(int argc, char *argv[], char *envp[]) { FILE *fd; // File pointer char *name; char *filename[]; name = getenv("MCEXEC_PLAYERNAME"); sprintf(filename,"/home/minecraft/freedonia/playerdata/deathlog-%s.txt",name); char buff[1024]; if ((fd = fopen(filename, "r")) != NULL) // open file { fseek(fd, 0, SEEK_SET); // make sure start from 0 while(!feof(fd)) { memset(buff, 0x00, 1024); // clean buffer fscanf(fd, "%[^\n]\n", buff); // read file *prefer using fscanf } printf("Last Line :: %s\n", buff); } else printf( "fail" ); } </code></pre> <p>here is the error i get while compiling using gcc</p> <pre><code>lastline.c: In function ‘main’: lastline.c:9: error: array size missing in ‘filename’ lastline.c:11: warning: passing argument 1 of ‘sprintf’ from incompatible pointer type /usr/include/stdio.h:341: note: expected ‘char * __restrict__’ but argument is of type ‘char **’ lastline.c:13: warning: passing argument 1 of ‘fopen’ from incompatible pointer type /usr/include/stdio.h:249: note: expected ‘const char * __restrict__’ but argument is of type ‘char **’ </code></pre>
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