gno/usr.bin/sort/tempnam.c

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1996-01-28 00:52:48 +00:00
#ifdef __CCFRONT__
#include <14:pragma.h>
#endif
/*
* #include <stdio.h>
*
* char *tempnam (const char *dir, const char *prefix);
*
* Generate a pathname for a temporary file.
*
* tempnam will select a directory for the temporary file by using the
* following criteria:
*
* If dir is not the NULL pointer, tempnam uses the pathname pointed to by
* dir as the directory,
*
* otherwise, tmpdir uses the value of the TMPDIR environment variable if
* the variable is defined,
*
* otherwise the directory defined by P_tmpdir in the stdio.h header file
* if that directory is writable by the caller,
*
* otherwise, tempnam will use "/tmp" as a last resort.
*/
#ifdef __ORCAC__
#define __GNO__ 1
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#define max(A,B) (((A)<(B))?(B):(A))
#if !defined(__GNO__)
extern char *mktemp();
extern int access();
#endif
static char seed[4]="AAA";
#if (defined __GNO__)
static char pbrk;
#else
# define pbrk '/';
#endif
/* BSD stdio.h doesn't define P_tmpdir, so let's do it here */
#ifndef P_tmpdir
static char *P_tmpdir = "/tmp";
#endif
static char *
cpdir(char *buf, char *str)
{
char *p;
char *path;
if(str != NULL) {
#if defined(__GNO__)
/* get the path delimiter */
if (strchr(str,':')) pbrk = ':';
else if (strchr(str,'/')) pbrk = '/';
else {
if ((path=getenv("PATH"))==NULL) pbrk = '/';
else pbrk = (strchr(path,':')) ? ':' : '/';
}
#endif
(void) strcpy(buf, str);
p = buf - 1 + strlen(buf);
if(*p == pbrk) *p = '\0';
}
return(buf);
}
char *
tempnam (char *dir, char *prefix)
/* dir -- use this directory please (if non-NULL) */
/* prefix -- use this (if non-NULL) as filename prefix */
{
register char *p, *q, *tmpdir;
int tl=0, dl=0, pl;
/* create a buffer <p> that's as large as necessary */
pl = strlen(P_tmpdir);
if( (tmpdir = getenv("TMPDIR")) != NULL ) tl = strlen(tmpdir);
if( dir != NULL ) dl = strlen(dir);
if( (p = malloc((unsigned int)(max(max(dl,tl),pl)+16))) == NULL )
return(NULL);
*p = '\0';
#if defined (__GNO__)
if( (dl == 0) || (access( cpdir(p, dir), W_OK) != 0) )
if( (tl == 0) || (access( cpdir(p, tmpdir), W_OK) != 0) )
if( access( cpdir(p, P_tmpdir), W_OK) != 0 )
if( access( cpdir(p, "/tmp"), W_OK) != 0 )
return(NULL);
#else /* not __GNO__ */
if( (dl == 0) || (access( cpdir(p, dir), 3) != 0) )
if( (tl == 0) || (access( cpdir(p, tmpdir), 3) != 0) )
if( access( cpdir(p, P_tmpdir), 3) != 0 )
if( access( cpdir(p, "/tmp"), 3) != 0 )
return(NULL);
#endif /* not __GNO__ */
(void) strcat(p, "/");
if(prefix)
{
*(p+strlen(p)+5) = '\0';
(void)strncat(p, prefix, 5);
}
(void)strcat(p, seed);
(void)strcat(p, "XXXXXX");
q = seed;
while(*q == 'Z') *q++ = 'A';
++*q;
if(*mktemp(p) == '\0') return(NULL);
return(p);
}