/* 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) { unsigned i ; /* index */ int len ; static char fspec[NSTRING]; /* full path spec to search */ #if ENVFUNC char *path; /* environmental PATH variable */ #endif len = sizeof fspec - strlen( fname) - 1 ; if( len < 0) return NULL ; #if ENVFUNC if (hflag) { char *home; /* path to home directory */ home = getenv("HOME"); if (home != NULL) { if( len > (int) strlen( home) + 1) { /* 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 */ if( len >= 0) { 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 */ int cnt ; cnt = len ; /* build next possible file spec */ sp = fspec; while( *path && (*path != PATHCHR)) { if( cnt-- > 0) *sp++ = *path ; path += 1 ; } if( cnt >= 0) { /* 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++) if( len >= (int) strlen( pathname[ i])) { strcpy( fspec, pathname[ i]) ; strcat( fspec, fname); /* and try it out */ if( fexist( fspec)) return fspec ; } return NULL; /* no such luck */ }