diff options
Diffstat (limited to 'reference/C/CONTRIB/SNIP/pushdir.c')
| -rwxr-xr-x | reference/C/CONTRIB/SNIP/pushdir.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/reference/C/CONTRIB/SNIP/pushdir.c b/reference/C/CONTRIB/SNIP/pushdir.c new file mode 100755 index 0000000..362922c --- /dev/null +++ b/reference/C/CONTRIB/SNIP/pushdir.c @@ -0,0 +1,192 @@ +/*
+** PushDir() and PopDir()
+**
+** Original Copyright 1988-1991 by Bob Stout as part of
+** the MicroFirm Function Library (MFL)
+**
+** This subset version is an expanded version of the one
+** originally published by the author in Tech Specialist
+** magazine and is hereby donated to the public domain.
+*/
+
+#include <dos.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#ifdef __TURBOC__
+ #include <dir.h>
+#else
+ #include <direct.h>
+#endif
+
+#define DIR_STACK_SIZE 8
+#define MAX_FLEN 67
+
+typedef enum {ERROR = -1, FALSE, TRUE} LOGICAL;
+
+#define BOOL(x) (!(!(x)))
+
+/*
+** NOTE: Uses the author's chdrv(), also in SNIPPETS!
+*/
+
+int chdrv(int);
+
+static int PushDir_stack_ptr;
+static char PushDir_stack[DIR_STACK_SIZE][MAX_FLEN];
+
+/*
+** PushDir()
+**
+** Like chdir(), except a drive may be specified and the old directory
+** is saved.
+**
+** Arguments: 1 - newdir, the buffer containing the new directory name
+**
+** Returns: -1 - stack overflow
+** 0 - error
+** 1 - success, still on same drive
+** 2 - success, changed drive
+**
+** Side effects: Converts name in newdir to upper case and prepends
+** a drive letter.
+**
+** CAUTION: Since a drive will be prepended to newdir, it's buffer
+** should be at at least MAX_FLEN long.
+*/
+
+int PushDir(char *newdir)
+{
+ char pname[MAX_FLEN];
+ char drive[3];
+ char *target = &pname[2];
+ int new_drv = 0, ercode = 0;
+ static int init = 0;
+
+ if (!init)
+ PushDir_stack_ptr = init = -1;
+ if (DIR_STACK_SIZE <= ++PushDir_stack_ptr)
+ {
+ ercode = -1;
+ goto ErrEx;
+ }
+ getcwd(PushDir_stack[PushDir_stack_ptr], MAX_FLEN);
+ strupr(PushDir_stack[PushDir_stack_ptr]);
+ strncpy(drive, PushDir_stack[PushDir_stack_ptr], 2);
+ drive[2] = '\0';
+ if (':' == newdir[1])
+ { /* If a drive is specified */
+ strupr(newdir);
+ strcpy(pname, newdir);
+ if (strchr(target, ':')) /* if filename is illegal */
+ goto ErrEx;
+ if (*drive != *newdir)
+ {
+ if (ERROR == chdrv(newdir[0] - 'A'))
+ { /* If the drive is invalid */
+ goto ErrEx;
+ }
+ else new_drv = 1;
+ }
+ }
+ else
+ { /* If a drive isn't specified */
+ if (!strchr(strupr(newdir), ':'))
+ { /* If legal filename */
+ strcpy(pname, drive);
+ strcat(pname, newdir);
+ strcpy(newdir, pname);
+ }
+ else
+ { /* If filename is illegal */
+ goto ErrEx;
+ }
+ }
+
+ if (*target)
+ {
+ if (chdir(target))
+ {
+ if (1 == new_drv) /* We already changed drives */
+ chdrv(*drive - 'A'); /* Go home before exit */
+ goto ErrEx;
+ }
+ }
+ return (new_drv + 1);
+ErrEx:
+ --PushDir_stack_ptr;
+ return (ercode);
+}
+
+/*
+** PopDir()
+**
+** Like chdir(), except goes to the drive/directory specified on the
+** top of the PushDir stack.
+**
+** Arguments: none
+**
+** Returns: -1 - stack empty
+** 0 - error - stack pointer unchanged
+** 1 - success, still on same drive
+** 2 - success, changed drive
+**
+** Side effects: none
+**
+** CAUTION: chdir() or chdrv() should not be called between PushDir-
+** PopDir calls.
+*/
+
+int PopDir(void)
+{
+ char I_am_here[MAX_FLEN], target_drv, *target;
+ int new_drv = 0;
+
+ if (0 > PushDir_stack_ptr)
+ return -1;
+ getcwd(I_am_here, MAX_FLEN);
+ target = &PushDir_stack[PushDir_stack_ptr][2];
+ target_drv = PushDir_stack[PushDir_stack_ptr][0];
+ if (I_am_here[0] != target_drv)
+ {
+ if (ERROR == chdrv(target_drv - 'A'))
+ return 0;
+ new_drv = 1;
+ }
+ if (!chdir(target))
+ {
+ --PushDir_stack_ptr;
+ return (1 + new_drv);
+ }
+ else return 0;
+}
+
+/*
+** isdir()
+**
+** Checks to see if a drive and/or path are a valid directory.
+**
+** Arguments: 1 - dir, the buffer containing the new directory name
+**
+** Returns: ERROR - push/popdir stack overflow
+** FALSE - not a valid directory
+** TRUE - valid directory
+**
+** Side effects: Converts name in dir to upper case and prepends a
+** drive letter.
+**
+** CAUTION: Since a drive will be prepended to newdir, it's buffer
+** should be at at least MAX_FLEN long.
+*/
+
+int isdir(char *dir)
+{
+ int ercode;
+
+ if (-1 == (ercode = PushDir(dir)))
+ return ercode;
+ if (ercode)
+ PopDir();
+ return BOOL(ercode);
+}
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