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POIssue with using execvp()
 

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  1. POIssue with using execvp()
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    <pre><code>#include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;unistd.h&gt; #include &lt;string.h&gt; #include &lt;errno.h&gt; #include &lt;sys/types.h&gt; #include &lt;sys/wait.h&gt; extern int errno; void parseArgs(char *path, char *argv[]) { while (*path != '\0') { while (*path == ' ' || *path == '\t' || *path == '\n') { *path++ = '\0'; } *argv++ = path; while (*path != '\0' &amp;&amp; *path != ' ' &amp;&amp; *path != '\t' &amp;&amp; *path != '\n') { path++; } } *argv = '\0'; } int execArgs(char *argv[], int amp) { pid_t process; int check; if ((process = fork()) &lt; 0) { fprintf(stderr, "Forking child failed\n%s\n", strerror(errno)); errno = 0; return EXIT_FAILURE; } else if (process == 0) { if (execvp(*argv, argv) &lt; 0) { fprintf(stderr, "Execution failed\n%s\n", strerror(errno)); errno = 0; return EXIT_FAILURE; } } else { while (wait(&amp;check) != process) { //do nothing } } return EXIT_SUCCESS; } int main (void) { char path[1024]; char *argv[64]; //int amp = 0; while (1) { printf("[root@localhost]$ "); fgets(path, 1024, stdin); puts(""); parseArgs(path, argv); if (strcmp(argv[0], "exit") == 0) { return EXIT_SUCCESS; } execArgs(argv, 0); } } </code></pre> <p>I'm having an issue here. The problem seems to be a parse error, because whenever I try to <code>ls</code> a directory, I get <code>ls: cannot access : No such file or directory</code>. The odd thing is, if I go <code>ls ..</code> I get:</p> <pre><code>ls: cannot access : No such file or directory ..: cat cat.c cat.c~ m4 </code></pre> <h3>NOTE: The above are the contents of the dir one level up!</h3> <p>Furthermore - and I suspect the issues are linked - I cannot <code>cd</code> into directories, however I'm not 100% sure of this as it does not throw anything like directory does not exist; I just get a blank space (but my cwd does not update).</p> <p>Any help would be appreciated!</p> <p>For Reference, some test inputs</p> <pre><code>[thanasi@localhost m4]$ ./cli [root@localhost /home/thanasi/Systems Programming/m4]$ ls ls: cannot access : No such file or directory [root@localhost /home/thanasi/Systems Programming/m4]$ ls .. ls: cannot access : No such file or directory ..: cat cat.c cat.c~ m4 [root@localhost /home/thanasi/Systems Programming/m4]$ cd test [root@localhost /home/thanasi/Systems Programming/m4]$ cd /test /usr/bin/cd: line 2: cd: /test: No such file or directory [root@localhost /home/thanasi/Systems Programming/m4]$ ^C </code></pre> <p>And confirmation dir 'test' does exist:</p> <pre><code>[thanasi@localhost m4]$ ls -al total 36 drwxrwxr-x. 3 thanasi thanasi 4096 Mar 17 22:00 . drwxrwxr-x. 3 thanasi thanasi 4096 Mar 17 20:36 .. -rwxrwxr-x. 1 thanasi thanasi 13175 Mar 17 22:00 cli -rw-rw-r--. 1 thanasi thanasi 1222 Mar 17 22:00 cli.c -rw-rw-r--. 1 thanasi thanasi 1221 Mar 17 22:00 cli.c~ drwxr-xr-x. 2 root root 4096 Mar 17 21:32 test </code></pre>
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    1. PTQuestion
    1. USThanasi Poulos
    1. USThanasi Poulos
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    1. PO
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    1. VO
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      1. POIssue with using execvp()
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. CO@JoachimPileborg, I'm not exactly sure where that issue occurs; afaik I do that with *argv = '\0' in parseArgs.
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      1. POIssue with using execvp()
      1. USThanasi Poulos
    2. CO@capncoolio `*argv = '\0';` is confusing, make it `*argv = NULL;` there to be clearly understandable.
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      1. POIssue with using execvp()
      1. USDaniel Fischer
    3. COI suggest you use a debugger and step though the parsing function to make sure it sets up the argument array properly.
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      1. POIssue with using execvp()
      1. USSome programmer dude
 

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