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Top Forums Programming How to turn argv[1] into a string in C? Post 302496225 by fpmurphy on Saturday 12th of February 2011 10:41:33 PM
Old 02-12-2011
Quote:
Code:
  if ((str = malloc(len + 1)) != NULL) {
       bzero(str, len + 1); /* Does the example warrant zeroing out the memory?; bzero is a deprecated function, use memset instead */
       strncpy(str, argv[1], len);
       printf("argv[1] = %s\n", str);
    } else {  
           exit(EXIT_FAILURE);   /* if not, it will try to free memory not allocated */
    }

The comment regarding trying to free memory is patently incorrect as I specifically handled that case with
Code:
char *str = (char *)NULL;

The long starting practice since the dawn of the C language is that if the argument to free() is a null pointer, no action shall occur. This was and is codified by all versions of the various C standards.

As regards the comment that bzero() is deprecated, yes it is deprecated on some platforms and in some standards and specifications but is not depreciated in others. I did not claim any particular conformance so the comment lacks standing.

Last edited by fpmurphy; 02-13-2011 at 12:25 PM..
 

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isaexec(3C)						   Standard C Library Functions 					       isaexec(3C)

NAME
isaexec - invoke isa-specific executable SYNOPSIS
#include <unistd.h> int isaexec(const char *path, char *const argv[], char *const envp[]); DESCRIPTION
The isaexec() function takes the path specified as path and breaks it into directory and file name components. It enquires from the running system the list of supported instruction set architectures; see isalist(5). The function traverses the list for an executable file in named subdirectories of the original directory. When such a file is located, execve() is invoked with argv[] and envp[]. See exec(2). RETURN VALUES
If no file is located, isaexec() returns ENOENT. Other return values are the same as for execve(). EXAMPLES
Example 1: Example of isaexec() function. On a system whose isalist is sparcv7 sparc the program int main(int argc, char *argv[], char *envp[]) { return (isaexec("/bin/thing", argv, envp)); } will look first for an executable file named /bin/sparcv7/thing, then for an executable file named /bin/sparc/thing. It will invoke execve() on the first executable file it finds named thing. On that same system, a program called /u/bin/tofu can cause either /u/bin/sparcv7/tofu or /u/bin/sparc/tofu to be invoked using the follow- ing code: int main(int argc, char *argv[], char *envp[]) { return (isaexec(getexecname(), argv, envp)); } ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |Safe | +-----------------------------+-----------------------------+ |Interface Stability |Stable | +-----------------------------+-----------------------------+ SEE ALSO
exec(2), getexecname(3C), attributes(5), isalist(5) SunOS 5.10 20 Mar 1998 isaexec(3C)
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