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uemacs/flook.c

153 lines
2.7 KiB
C

/* flook.c -- implements flook.h */
#include "flook.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "defines.h"
#include "fileio.h"
/* possible names and paths of help files under different OSs */
const char *pathname[] = {
#if MSDOS
"emacs.rc",
"emacs.hlp",
"\\sys\\public\\",
"\\usr\\bin\\",
"\\bin\\",
"\\",
""
#endif
#if V7 | BSD | USG
".emacsrc",
"emacs.hlp",
#if PKCODE
"/usr/global/lib/", "/usr/local/bin/", "/usr/local/lib/",
#endif
"/usr/local/", "/usr/lib/", ""
#endif
#if VMS
{
"emacs.rc", "emacs.hlp", "",
#if PKCODE
"sys$login:", "emacs_dir:",
#endif
"sys$sysdevice:[vmstools]"
#endif
};
#define PATHNAME_SIZE (sizeof pathname / sizeof pathname[ 0])
/*
* does <fname> exist on disk?
*
* char *fname; file to check for existance
*/
boolean fexist( const char *fname)
{
FILE *fp;
/* try to open the file for reading */
fp = fopen(fname, "r");
/* if it fails, just return false! */
if (fp == NULL)
return FALSE;
/* otherwise, close it and report true */
fclose(fp);
return TRUE;
}
/*
* Look up the existance of a file along the normal or PATH
* environment variable. Look first in the HOME directory if
* asked and possible
*
* char *fname; base file name to search for
* boolean hflag; Look in the HOME environment variable first?
*/
char *flook( const char *fname, boolean hflag)
{
int i; /* index */
static char fspec[NSTRING]; /* full path spec to search */
#if ENVFUNC
char *path; /* environmental PATH variable */
if (hflag) {
char *home; /* path to home directory */
home = getenv("HOME");
if (home != NULL) {
/* build home dir file spec */
strcpy(fspec, home);
strcat(fspec, "/");
strcat(fspec, fname);
/* and try it out */
if( fexist( fspec))
return fspec ;
}
}
#endif
/* always try the current directory first */
strcpy( fspec, fname) ;
if( fexist( fspec))
return fspec ;
#if ENVFUNC
#if V7 | USG | BSD
#define PATHCHR ':'
#else
#define PATHCHR ';'
#endif
/* get the PATH variable */
path = getenv("PATH");
if (path != NULL)
while (*path) {
char *sp; /* pointer into path spec */
/* build next possible file spec */
sp = fspec;
while (*path && (*path != PATHCHR))
*sp++ = *path++;
/* add a terminating dir separator if we need it */
if (sp != fspec)
*sp++ = '/';
*sp = 0;
strcat(fspec, fname);
/* and try it out */
if( fexist( fspec))
return fspec ;
if (*path == PATHCHR)
++path;
}
#endif
/* look it up via the old table method */
for( i = 2; i < PATHNAME_SIZE ; i++) {
strcpy(fspec, pathname[i]);
strcat(fspec, fname);
/* and try it out */
if( fexist( fspec))
return fspec ;
}
return NULL; /* no such luck */
}