Usenet 1993 July/InfoMagic USENET CD-ROM July 1993.ISO/sources/unix/volume13/e

Internet Message Format | 1988-01-31 | 49.2 KB

Subject:  v13i060:  Friendly front-end to vi
Newsgroups: comp.sources.unix
Sender: sources
Approved: [e-mail]

Submitted-by: Crocodile Dundee <[e-mail]>
Posting-number: Volume 13, Issue 60
Archive-name: e

Basically e is a command line preprocessor to get you into vi with ease.
I find it useful - even given a shell with history and command completion.
It keeps a short history of the files that have been e'ed most recently in
each directory. Thus it is nice to be able to do

cd somewhere
e

and get straight into the file you were last working on in the directory
"somewhere". It also allows fast cross-directory editing and does obvious
spelling corrections.



#!/bin/sh
# This is a shell archive.  Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
#
# Contents:  README e.cat e.1 Makefile MANIFEST MODS e.h e.c

echo x - README
sed 's/^@//' > "README" <<'@//E*O*F README//'
README - version 1.2
--------------------

BLURB.
======

Basically e is a command line preprocessor to get you into vi with ease.
I find it useful - even given a shell with history. It keeps a short history
of the files that have been e'ed most recently in each directory. Thus it is
nice to be able to do

cd somewhere
e

and get straight into the file you were last working on in the directory
"somewhere". It also allows fast cross-directory editing and does obvious
spelling corrections.

DOCUMENTATION
=============

Documentation and examples can be found in the man page in e.1.
This is in troff -man format. e.cat contains the troffed output of e.1.

MAKING
======

Before making you should change the #define VI line in e.h depending on the
location of your vi. Also change the DESTDIR line in Makefile.

This will run just fine on BSD4.[23]. Also on Ultrix-32.
It appears to work on a SUN as well, just #define NFS in e.h
I am told it will also run on sysV, just #define sysV in e.h


THANKS
======

To Phil Oldiges and Simon Brown for the man page and the SysV portability
changes.

This appears free of major bugs (famous last words) - I'd like to hear
about anything that goes wrong and/or fixes/enhancements. Comments on
what is wrong and how it could be better/faster are also welcome...



-------------------------------------------------------------------------------
Terry Jones, Department Of Computer Science, University Of Waterloo
             Waterloo Ontario Canada N2L 3G1

{ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones
[e-mail].{cdn,edu} [e-mail]
[e-mail] [from oz, [e-mail]@munnari]
-------------------------------------------------------------------------------

@//E*O*F README//
chmod u=rw,g=rx,o=rx README

echo x - e.1
sed 's/^@//' > "e.1" <<'@//E*O*F e.1//'
@.TH E P "December 15, 1987"
@.SH NAME
e \- command line preprocessor for the vi(1) editor.
@.SH SYNOPSIS
@.B e
[
@.B option
] [
@.B file
] ...
@.SH DESCRIPTION
@.I e
is an interface to
@.IR vi (1)
that maintains a history of the most recently \fIe\fR'ed
files for each directory. Its invocation syntax is (almost) a superset of
that of \fIvi\fR.
@.PP
A file called .e is kept in each directory. This contains the history and is
kept to a small length (<10 lines). Spelling corrections are suggested for
simple mistakes (wrong character, omitted character, interchanged
characters, extra character).
The history file is rearranged with each use to place the last \fIe\fR'ed
file at the end of the list. Duplicate entries are removed.
If set, the environment variable VIPATH is read and the directories it contains
are searched for an existing file with the same name before a new file is
created. Thus one can vi across directories with ease.
@.SH INVOCATION
A list of the command line variations is given below.
[x] indicates that "x" is optional. "cmd" means a
@.I vi
command.
@.TP 18
@.B e
Invokes \fIvi\fR on the last file that was \fIe\fR'ed in this directory.
@.TP 18
@.B e \-
Prints the history for this directory and allows selection
of a previous file - or a new one.
@.TP 18
@.B e .
Prints the history for this directory without asking for input.
@.TP 18
@.B e \-t tag
Invokes \fIvi\fR \-t tag
@.TP 18
@.B e \-r
Invokes \fIvi\fR \-r
@.TP 18
@.B e \-r file
Invokes \fIvi\fR \-r file
@.TP 18
@.B e \-pat
\fIvi\fR's the last file that was \fIe\fR'ed with the string "pat" on
the command line.
@.TP 18
@.B e +[cmd]
\fIvi\fR's the last file that was \fIe\fR'ed in this directory but executes
command "cmd" on the way into.
@.I vi
@.TP 18
@.B e [+[cmd]] file
\fIvi\fR's the file and adds it to the history list. Minor spelling
corrections are suggested if "file" does not exist but is close
(in spelling) to some file that does.
@.TP 18
@.B e [+[cmd]] files
\fIvi\fR's the files and adds them as a single entry to the history.
@.SH EXAMPLE
@.PP
With a ".e" file containing:
@.in 1.0i
@.B fred.c
@.br
@.B jane
@.br
@.B alison
@.br
@.B +/main pete.c
@.br
@.B bigmac
@.br
@.B fries juice
@.br
@.PP 2
The command "\fBe .\fR" will give:
@.in 1.0i
@.B [5]: fred.c
@.br
@.B [4]: jane
@.br
@.B [3]: alison
@.br
@.B [2]: +/main pete.c
@.br
@.B [1]: bigmac
@.br
@.B [0]: fries juice
@.br
@.TP 12
@.B e
will get you fries and then juice.
@.TP 12
@.B e \-
will present the same as shown for "\fBe .\fR" above
but will ask for a number or another filename.
Carriage return is equivalent to zero (i.e. the last filename),
backspace or interrupt will quit.
@.TP 12
@.B e \-ali
will get you alison.
@.TP 12
@.B e +/ketchup
will get you fries and juice, searching for ketchup in fries.
@.TP 12
@.B e bigamc
will ask if you want to correct to bigmac.
"n" will not do the correction,
"Q" or "q" will quit, anything else will go ahead.
If there is more than one possible correction you will be prompted for each in
turn. A response of "N" will means that you really want what you typed, no
further corrections will be offered.
@.SH "ENVIRONMENT VARIABLES"
With an environment variable VIPATH set to "$HOME /usr/include/sys",
@.B "e inode.h"
will prompt you with /usr/include/sys/inode.h
if no file called inode.h exists in the current directory or your home
directory. You can say "y", "n" or "q" to accept, reject or quit.
If you accept then the file is put into the history. Spelling corrections
are not suggested across directories.
There is (of course) no need to put "." in your VIPATH. Doing so will just slow
things down and cannot possibly be of help.
This should be clear, "." is always searched first for the given filename.
Putting it into your VIPATH will have it searched twice. The directory names
in VIPATH may be separated by white space (including newlines) and colons.
@.SH NOTES
When using
@.B "e -"
the terminal is put into cbreak mode. If the first
character typed is a digit (in the acceptable range of history items)
then you will get that history item without further ado. Thus if you
have a file called 4play and you try and
@.B "e"
it from within a
@.B "e -"
then you'll probably end up in the wrong place.
This is to say you'll get the file that was the 4th last in the history.
@.PP
The history length must be less than or equal to 9 (the code sets
it to 8 at present).
The problem with having more is that with
@.B "e -"
you go into cbreak
and the first digit entered (say \fIn\fP) is taken to mean
"I want the \fIn\fRth last file". This saves the need for hitting return.
With the history being kept as a most recently used list, 8 file names
should be enough.
@.SH BUGS
The first character on a select line cannot be backspaced over.
@.SH "THINGS TO DO"
Make .exrc files be inherited when \fIe\fR'ing across directories.
@.br
Do spelling corrections across directories.
@.br
Plenty of fancy things.
Keep a single .e file in $HOME and then it is possible to use history features
in unwriteable directories etc. (suggested by ian! allen)
@.br
Version 2 will be a complete rewrite and will clean up the above and hopefully
add cross directory spelling correction and other useful things.
@.SH "SEE ALSO"
ex (1), edit (1).
@.SH AUTHOR
Terry Jones
@.br
Department of Computer Science
@.br
University of Waterloo

@.\"
@.\" Man page for e. Version 1.2
@.\"
@.\"    ------------------------------------------------------------------------
@.\"    Terry Jones, Department Of Computer Science, University Of Waterloo
@.\"         Waterloo Ontario Canada N2L 3G1
@.\"
@.\"    {ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones
@.\"    [e-mail].{cdn,edu} [e-mail]
@.\"    [e-mail]
@.\"    -------------------------------------------------------------------------
@.\"
@//E*O*F e.1//
chmod u=rw,g=rx,o=rx e.1

echo x - Makefile
sed 's/^@//' > "Makefile" <<'@//E*O*F Makefile//'
#
# Makefile for e version 1.2
#

CC = /bin/cc
CFLAGS = -O
DESTDIR = /u/tcjones/bin
DEST = $(DESTDIR)/e
OBJ = e.o
HEADERS = e.h

$(DEST) : $(HEADERS) $(OBJ)
    $(CC) $(CFLAGS) -o $(DEST) $(OBJ)
    strip $(DEST)
@//E*O*F Makefile//
chmod u=rw,g=rx,o=rx Makefile

echo x - MANIFEST
sed 's/^@//' > "MANIFEST" <<'@//E*O*F MANIFEST//'
The shar for version 1.2 should come with eight files

    Makefile
    MANIFEST
    README
    e.1
    e.c
    e.cat
    e.h
    MODS
@//E*O*F MANIFEST//
chmod u=rw,g=rx,o=rx MANIFEST

echo x - MODS
sed 's/^@//' > "MODS" <<'@//E*O*F MODS//'
e Modification History.
=======================




Version 1.1 changes          October 1987.
==========================================

- Added "VIPATH" environment variable.
- Fixed bug with argument lists that exceeded ARG_CHARS chars in multiple().
- Added #ifdef statements to enable compilation on a SUN.
- Put #defines etc into e.h as they were getting in the way.



Version 1.2 changes          December 1987.
===========================================

- Made the numbering on "e -" the same as for "e .".
- System V port (thanks to Simon Brown).
- Added man page (thanks to Phil Oldiges).
- Fixed handling of the VIPATH variable so that it doesn't screw up
    when there is more than one delimiter. Added new delimiters.
- Cleaned up terminal handling to use ioctl().
- Cleaned up error handling.
- Fixed (for sure this time) the bug with long argument lists.
- Made returns consistent in check().
- Flagged suspected unsatisfied symbolic link in check().
- Added #define called E_PATH which contains the name of the environment
    variable containing the PATH for cross directory stuff. (set to "VIPATH").
- Added E_MODE #define for the protection mode for .e (set to 0644).
- Fixed spelling correction to offer all likely targets in a directory, not
    just the first encountered. Added 'N' option to say "I meant what I said,
    don't give me more possible corrections."
- Comments!


To be added?
============

- Allow backspacing on a select line.
- Make .exrc files be inherited when e'ing across directories.
- Spelling corrections across directories.
- Plenty of fancy things.
- Keep a single .e file in $HOME and then it's easy to use the history in
   unwriteable directories etc. do this nicely with hashing/binary search etc.
   (suggested by ian! allen)




-------------------------------------------------------------------------------
Terry Jones, Department Of Computer Science, University Of Waterloo
             Waterloo Ontario Canada N2L 3G1

{ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones
[e-mail].{cdn,edu} [e-mail]
[e-mail] [from oz, [e-mail]@munnari]
-------------------------------------------------------------------------------

@//E*O*F MODS//
chmod u=rw,g=rx,o=rx MODS

echo x - e.h
sed 's/^@//' > "e.h" <<'@//E*O*F e.h//'
/*
 * e.h for e version 1.2
 * =====================
 *
 *------------------------------------------------------------------------------
 * terry jones, department of computer science, university of waterloo
 *                waterloo ontario canada N2L 3G1

 * {ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones
 * [e-mail].{cdn,edu} [e-mail]
 * [e-mail]
 *------------------------------------------------------------------------------
 */




/*
 * #includes common to all versions of uni*x
 *
 */


#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <signal.h>
#include <ctype.h>
#include <sys/param.h>



/*
 * un*x version dependent #includes
 *
 */


#ifdef sysV
#  ifdef GEC
#    include <local/ndir.h>
#  else
#    include <ndir.h>
#  endif
#  include <termio.h>
#  include <string.h>
#  include <fcntl.h>
#else
#  include <sys/dir.h>
#  ifdef NFS
#    include <time.h>
#    include <sys/vnode.h>
#    include <ufs/inode.h>
#    include <sgtty.h>
#  else
#    include <sys/inode.h>
#    include <sys/ioctl.h>
#  endif
#  include <strings.h>
#endif sysV




/*
 * un*x dependent #defines
 *
 */


#ifdef sysV
#  define VI "/usr/bin/vi"
#  define index strchr
#  define rindex strrchr
#else
#  define VI "/usr/ucb/vi"
#endif sysV


/*
 * Other checks...
 *
 */

#ifndef L_SET
# define L_SET 0
#endif

#ifndef IREAD
# define IREAD    0400
# define IWRITE    0200
#endif



/*
 * The #defines for things that aren't portability concerns.
 *
 */



#define HIST ".e"
#define HIST_LINES 8
#define HIST_CHARS 1024
#define E_PATH "VIPATH"
#define E_MODE 0644
#define ARG_CHARS 1024
#define MAX_ARGS 100
#define MAX_PATH 1024
#define BELL '\007'
#define O_READ 00004
#define G_READ 0004



/*
 * #defines for the terminal() function.
 *
 */

#define TERM_RECORD 0
#define TERM_SET 1
#define TERM_RESET 2



/*
 * STRUCT_ASST should be defined if your UN*X is capable of doing
 * structural assignment. This is (supposedly) true for System III, System V,
 * UNIX/32V, BSD4.[23], v8 and v9. It's also in ANSI C, but *not* in
 * "The C programming language" by Kernhigan & Ritchie.
 *
 * This #define is only used in the function terminal(). Leave STRUCT_ASST
 * defined and if it doesn't break you're ok. If it does, undefine it and
 * you'll definitely be ok (but things will run slower - even though you
 * wont notice that anyway.) Words words words. Ho hum.
 *
 */

#define STRUCT_ASST


/*
 * A slightly dangerous one. NEVER call this as (for example) "is_delim(cp++)"
 * Or the incrementing will be done 4 times (not one).
 */


#define is_delim(c) ((*c)==' '||(*c)==':'||(*c)=='\t'||(*c)=='\n')
@//E*O*F e.h//
chmod u=rw,g=rx,o=rx e.h

echo x - e.c
sed 's/^@//' > "e.c" <<'@//E*O*F e.c//'

/******************************************************************************
 #                                                                            #
 #                                                                            #
 # e - Command line preprocessor for vi.  Version 1.2 - November 1987.        #
 # ======================================================================     #
 #                                                                            #
 #                                                                            #
 # Terry Jones                                                                #
 # Department of Computer Science                                             #
 # University of Waterloo                                                     #
 # Waterloo, Ontario, Canada. N2L 3G1                                         #
 #                                                                            #
 # {ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones        #
 # [e-mail].{cdn,edu} [e-mail]                     #
 # [e-mail]                                           #
 #                                                                            #
 #*****************************************************************************/


#include "e.h"


/*
 * Globals. All in the name of ease and perhaps speed.
 *
 */

char history[HIST_CHARS];
char arg[ARG_CHARS];
char *hist[HIST_LINES];
char temp[HIST_CHARS];
char *tmp_file=".e_tmpXXXXXX";
char erase;
char *myname;


clean_up()
{
    /*
     * This is where we come when an interrupt is received.
     * Just get out after making sure things are tidy.
     *
     */

    e_error("\n%s","Interrupt.");
}



main(c,v)
int c;
char **v;
{
    myname=v[0];
    terminal(TERM_RECORD);

    /* handle SIGINT */
    if (signal(SIGINT,SIG_IGN)!=SIG_IGN){
        signal(SIGINT,clean_up);
    }



    /*
     * Process the command line. This gets a little messy as there are so
     * many ways e can be invoked. They are listed below and there is an
     * example provided in each case statement to illustrate the
     * particular case we are trying to handle.
     *
     * The idea in most cases is to get the arguments that will be passed
     * to vi into a character array (arg), and pass it to do_vi(). do_vi()
     * splits up the arguments and execs vi. Occasionally it is simpler and
     * do_vi() can be called as do_vi("fred").
     *
     *
     * Command Line Options.
     * =====================
     *
     * No arguments.
     *
     * (1) "e"
     *
     * One argument.
     *
     * (3) "e -"
     * (2) "e -n"                   Where n is some valid history item.
     * (4) "e -t"                   If they do this then they are in error!
     * (5) "e -r"
     * (6) "e -pat"
     * (7) "e +100"
     * (8) "e ."
     * (9) "e fred"
     *
     * Multiple arguments.
     *
     * (10) "e fred harry joe"      Also handles "e -t tag", "e -r file" etc.
     *
     */


    switch (c){
        case 1: {

            /*
             * Command line option (1).
             * Example: "e"
             *
             * Just go and vi the last file that was e'ed.
             *
             */

            last_file();
            do_vi(arg);
            break;
        }

        case 2:{
            switch ((*++v)[0]){

                case '-':{

                    if ((c=(*v)[1])=='\0'){

                        /*
                         * Command line option (2).
                         * Example: "e -"
                         *
                         * This is a select from history, ask what they want.
                         *
                         */

                        ask_hist();
                        do_vi(arg);
                    }
                    else if (isdigit(c)){

                        /*
                         * Command line option (3).
                         * Example: "e -3"
                         *
                         * Get the nth last file from the history and vi it.
                         *
                         */

                        nth_hist(c-'0');
                        do_vi(arg);
                    }
                    else if (c=='t'&&(*v)[2]=='\0'){

                        /*
                         * Command line option (4).
                         * Example: "e -t"
                         *
                         * This is an empty tag - ignore it.
                         * They have made a mistake, but let vi tell them.
                         *
                         */

                        do_vi(*v);
                    }
                    else if (c=='r'&&(*v)[2]=='\0'){

                        /*
                         * Command line option (5).
                         * Example: "e -r"
                         *
                         * A recover, just pass it to vi and don't interfere.
                         *
                         */

                        do_vi(*v);
                    }
                    else{

                        /*
                         * Command line option (6).
                         * Example: "e -pat"
                         *
                         * This is a pattern - try to match it.
                         *
                         */

                        find_match(++*v);
                        do_vi(arg);
                    }
                    break;
                }

                case '+':{

                    /*
                     * Command line option (7).
                     * Example: "e +100"
                     *
                     * A command, put it before the last file name.
                     *
                     */

                    insert_command(*v);
                    do_vi(arg);
                    break;
                }

                case '.':{

                    /*
                     * Command line option (8).
                     * Example: "e ."
                     * Example: "e .login"  (falls through to option (9)).
                     *
                     * Just give a history list if there is only a dot.
                     * Otherwise fall through as it must be a filename.
                     *
                     */

                    if ((*v)[1]=='\0'){
                        register ct;
                        register i;

                        read_hist();
                        ct=split_hist();

                        for (i=0;i<ct;i++){
                            fprintf(stderr,"\t[%d]: %s\n",ct-i-1,hist[ct-i-1]);
                        }
                        exit(0);
                    }
                    /*
                     * WARNING!
                     * The switch falls through in the case where there is a
                     * filename that starts with a period.
                     *
                     */
                }

                default :{

                    /*
                     * Command line option (9).
                     * Example: "e fred"
                     * Example: "e .login"  (fell through from option (8)).
                     *
                     * Looks like it's just a plain old file name. vi it!
                     *
                     */

                    normal(*v);
                    do_vi(arg);
                    break;
                }
            }
        }

        default:{

            /*
             * Command line option (10).
             * Example: "e fred harry joe"
             *
             * A bunch of arguments, fix the history & vi them all as normal.
             *
             */

            multiple(c,v,ARG_CHARS);
            do_vi(arg);
            break;
        }
    }
}



do_vi(thing)
char *thing;
{
    /*
     * Split the arguments (if any) in 'thing' up and exec vi on them.
     * The arguments must be space separated.
     *
     */
    char *args[MAX_ARGS];
    char *this,*next;
    register i;

    args[0]="vi";
    args[1]=thing;

    i=1;
    while (*thing!='\0'&&(thing=index(thing,' '))!=NULL){
        *thing++='\0';
        if (*thing!='\0'){
            args[++i]=thing;
        }
    }
    args[++i]=NULL;

    if (execvp(VI,args)==-1){
        e_error("%s %s","Could not execvp",VI);
    }
}



read_hist()
{
    /*
       Read the history file and break it up into lines in the global variable
       'history'. Do the appropriate checks to see that it exists.
    */

    register vh;
    register bytes;
    register offset;
    struct stat buf;

    /*
     * If there is no history file then say so and get out of here - they
     * had no business asking for access to the history.
     *
     */

    if ((vh=open(HIST,O_RDONLY))==-1){
        e_error("%s %s","Could not open",HIST);
    }

    /* Stat it */
    if (fstat(vh,&buf)==-1){
        e_error("%s %s","Could not stat",HIST);
    }

    /*
     * Set 'offset' so that we can read the last portion of the history
     * file only. If there are less than HIST_CHARS characters in the
     * file then we will start reading at 0, otherwise at HIST_CHARS
     * characters before the end of the file.
     *
     */

    offset=(int)buf.st_size-HIST_CHARS<0 ? 0 : buf.st_size-HIST_CHARS;

    /* Move (if it's non zero) to that place in the file. */

    if (offset&&lseek(vh,(long)offset,L_SET)==-1){
        e_error("%s %s","Could not lseek in",HIST);
    }

    /* And read. */
    if ((bytes=read(vh,history,HIST_CHARS))==-1){
        e_error("%s %s","read: Could not read",HIST);
    }

    /* If we didn't come up with ANYTHING we may as well leave. */
    if (!bytes){
        e_error("%s %s %s","Empty",HIST,"file.");
    }

    /* Zap the newline (which *should* be there) for now. */
    if (history[--bytes]=='\n'){
        history[bytes]='\0';
    }

    /* And get out of here. */
    return(bytes);
}



last_file()
{
    /*
     * Get the last name from the 'history' array and put it into 'arg'.
     *
     */

    read_hist();
    if (index(history,'\n')==NULL){
        if (*history=='\0'){
            e_error("%s %s",HIST,"has a line with no newline character.");
        }
        else{
            sprintf(arg,"%s",history);
        }
    }
    else{
        sprintf(arg,"%s",rindex(history,'\n')+1);
    }
}



split_hist()
{
    /*
     * Set the array of pointers in 'hist' to point to the succesive names
     * in the 'history' array. These are delimited (presumably) by newlines
     * and so they're easy to catch.

     * What in fact is done is that the history array is copied and we set
     * a pointer (in "hist") to the start of each new item and set the
     * newline characters to be NULLs. This way we don't mess up the history
     * array as we will want it intact later on (maybe).
     *
     */

    char *tmp;
    register count;

    /* Copy it. */
    sprintf(temp,"%s",history);

    /*
     * Now run through breaking it up, setting pointers and return the number
     * of lines we found.
     *
     */

    for (count=0;count<HIST_LINES;count++){
        if ((tmp=hist[count]=rindex(temp,'\n'))==NULL){
            break;
        }
        *tmp='\0';
        hist[count]++;
    }
    if (count<HIST_LINES){
        hist[count++]=temp;
    }
    return(count);
}



nth_hist(n)
int n;
{
    /*
     * Get the nth last filename from the list. Make use (of course) of
     * read_hist and split_hist.
     *
     */

    register count;
    register i;

    read_hist();
    count=split_hist();
    if (n>count-1){
        if (count>1){
            e_error("%s %d %s","Only",count,"history items exist.");
        }
        else{
            e_error("%s","Only one history item exists.");
        }
    }
    sprintf(arg,"%s",hist[n]);

    /* Rebuild the history with the selected name at the bottom. */

    reconstruct(n,count);
}



ask_hist()
{
    /*
     * Ask the outside world which of the files in the history is wanted.
     * set the terminal to cbreak.
     *
     */

    register i;
    register count;
    char *last;
    register option;
    struct sgttyb blk;

    /* Read and split the history file. */
    read_hist();
    count=split_hist();

    /* Print the history. */
    for (i=0;i<count;i++){
        fprintf(stderr,"\t[%d]: %s\n",count-i-1,hist[count-i-1]);
    }

    /* Give them a prompt (of sorts). */
    fprintf(stderr,"select -> ");

    /* Set the terminal up. */
    terminal(TERM_SET);

    /* Get their response. */
    option=getc(stdin);

    /* Make the terminal 'safe' again. */
    terminal(TERM_RESET);

    /*
     * Process the option and put the appropriate file name into the
     * arg variable.
     *
     */

    if (option=='\n'){
        /* They want the last file of the list. */
        fprintf(stderr,"%s\n",hist[0]);
        sprintf(arg,"%s",hist[0]);
        return;
    }
    else if (option==(int)erase){
        /* They want to leave. */
        fprintf(stderr,"\n");
        exit(1);
    }
    else if (option>='0'&&option<='0'+count-1){
        /* They have requested a file by its number. */
        option=option-'0';
        fprintf(stderr,"%s\n",hist[option]);
        sprintf(arg,"%s",hist[option]);
        reconstruct(option,count);
        return;
    }
    else{
        /*
         * Looks like they want to name a specific file. Echo the
         * character back to the screen.
         *
         */

        fprintf(stderr,"%c",option);
        arg[0]=option;
        i=1;
        while ((arg[i]=getc(stdin))!='\n'){
            i++;
        }
        arg[i]='\0';

        /* Seeing as they typed in the name, try and help with spelling. */
        if (!spell_help()){
            find();
        }

        /* If it is in the history then reconstruct and return. */
        for (i=0;i<count;i++){
            if (!strcmp(hist[i],arg)){
                reconstruct(i,count);
                return;
            }
        }

        /* Otherwise reconstruct, leaving out the oldest name. */
        reconstruct(count-1,count);
    }
}



FILE *
get_temp()
{
    /* Get ourselves a temporary file for the reconstructed history. */
    FILE *fp,*fopen();

    mktemp(tmp_file);
    if ((fp=fopen(tmp_file,"w"))==NULL){
        e_error("%s %s","Could not open temporary file",tmp_file);
    }
    return(fp);
}



close_temp(fp)
FILE *fp;
{
    /* Move the temporary file to be the new history. */
    FILE *fclose();

    if (fclose(fp)==(FILE *)EOF){
        e_error("%s %s","Could not close",tmp_file);
    }

    if (rename(tmp_file,HIST)!=0){
        e_error("%s %s %s %s","Could not rename",tmp_file,"to",HIST);
    }
}



terminal(what)
int what;
{
    /*
     * Handles the terminal. Must be first called as
     *
     * terminal(TERM_RECORD)
     *
     * which remembers the initial terminal charcteristics and sets up the
     * "erase" variable. Thereafter can be called as
     *
     * terminal(TERM_SET)  --  to turn on CBREAK and ECHO off.
     * terminal(TERM_RESET)  --  to set the terminal to its original state.
     *
     */

     register i;


#ifdef sysV
    static struct termio initial_blk;
    static struct termio set_blk;
#else
    static struct sgttyb initial_blk;
    static struct sgttyb set_blk;
#endif sysV



    switch(what){

        case TERM_RECORD:{

#ifdef sysV
            if (ioctl(0, TCGETA, &initial_blk)==-1){
                e_error("%s","Could not ioctl stdin.");
            }

#ifdef STRUCT_ASST
            /* Copy the structure in one hit. */
            set_blk=initial_blk;
#else
            /* Copy the structure field by field. */
            set_blk.c_iflag=initial_blk.c_iflag;
            set_blk.c_oflag=initial_blk.c_oflag;
            set_blk.c_cflag=initial_blk.c_cflag;
            set_blk.c_line=initial_blk.c_line;

            for (i=0;i<NCC;i++){
                set_blk.c_cc[i]=initial_blk.c_cc[i];
            }
#endif STRUCT_ASST

            /* And now set up the set_blk. */
            set_blk.c_lflag=(initial_blk.c_lflag &= ~(ICANON|ECHO|ECHONL));
            erase=set_blk.c_cc[VERASE];
            set_blk.c_cc[VMIN]=1;
            set_blk.c_cc[VTIME]=0;
#else
            if (ioctl(0, TIOCGETP, &initial_blk)==-1){
                e_error("%s","Could not ioctl stdin.");
            }

#ifdef STRUCT_ASST
            /* Copy the structure in one hit. */
            set_blk=initial_blk;
#else
            /* Copy the structure field by field. */
            set_blk.sg_ispeed=initial_blk.sg_ispeed;
            set_blk.sg_ospeed = initial_blk.sg_ospeed;
            set_blk.sg_erase = initial_blk.sg_erase;
            set_blk.sg_kill = initial_blk.sg_kill;
            set_blk.sg_flags = initial_blk.sg_flags;
#endif STRUCT_ASST


            /* And now set up the set_blk. */
            erase = set_blk.sg_erase;

            /* Go into CBREAK mode or stay that way if we are already. */
            set_blk.sg_flags |= CBREAK;

            /* Turn off echo. */
            set_blk.sg_flags &= ~ECHO;

#endif sysV

            break;
        }



        case TERM_SET:{

#ifdef sysV
            if (ioctl(0, TCSETA, &set_blk)==-1){
                e_error("%s","Could not ioctl stdin");
            }
#else
            if (ioctl(0, TIOCSETP, &set_blk)==-1){
                e_error("%s","Could not ioctl stdin");
            };
#endif sysV

            break;
        }





        case TERM_RESET:{

#ifdef sysV
            if (ioctl(0, TCSETA, &initial_blk)==-1){
                e_error("%s","Could not ioctl stdin");
            }
#else
            if (ioctl(0, TIOCSETP, &initial_blk)==-1){
                e_error("%s","Could not ioctl stdin");
            }
#endif sysV

            break;
        }


        default:{
            /* Look! - no ifdefs here. */
            e_error("%s %d","terminal() called with unknown parameter",what);
        }
    }
}



match(argument,pattern)
char    *argument;
char    *pattern;
{
    /*
     * Boneheaded but easy pattern matcher. Just see if the 'pattern'
     * exists anywhere in the 'argument'. Boyer-Moore who?
     * In general our patterns will be so short that it wouldn't be
     * worth the effort to set up a better algorithm.
     *
     */

    register length=strlen(pattern);

    while (strlen(argument)>=length){
        if (!strncmp(argument++,pattern,length)){
            return(1);
        }
    }
    return(0);
}



find_match(pattern)
char *pattern;
{
    /*
     * Find the name in the history list that contains the 'pattern'.
     * if it exists then put it into the 'arg' variable and otherwise
     * announce that a match couldn't be found and leave.
     *
     */

    register count;
    register i;

    /* Read and split the history file. */
    read_hist();
    count=split_hist();

    /*
     * Try for a match with each file in turn (note that we are working
     * from most-recently-used backwards - probably a good thing).
     *
     */

    for (i=0;i<count;i++){
        if (match(hist[i],pattern)){
            sprintf(arg,"%s",hist[i]);
            reconstruct(i,count);
            return;
        }
    }

    /* We couldn't match so get out of here. */
    e_error("%s \"%s\".","Unable to match with",pattern);
}



insert_command(command)
char *command;
{
    /*
     * They want the last file in the history but want to preceed it
     * this time with a command - no problems here.
     *
     */

    register count;
    char *place;

    /* read and split the history. */
    read_hist();
    count=split_hist();

    /*
     * If there was already a command there (indicated by a '+') then we
     * want to get rid of it. If there is a '+' but no ' ' (somewhere) after
     * it then the history file is in disarray and we will not try to recover.
     *
     */

    if (*hist[0]=='+'){
        if ((place=index(hist[0],' '))==NULL){
            e_error("%s %s",HIST,"file corrupted, + but no following space");
        }
        /* Move over white space - if there is any. */
        while (*place==' '||*place=='\t'){
            place++;
        }
    }
    else{
        /* There was no command preceeding the last file in the history. */
        place=hist[0];
    }

    /* Put the new command and the filename into 'arg' */
    sprintf(arg,"%s %s",command,place);

    /* Rebuild the history with the selected command and name at the bottom. */
    reconstruct(0,count);
}



reconstruct(except,count)
int except;
int count;
{
    /*
     * Reconstruct history file excepting the 'except' last.
     * So just copy all lines but the 'except'th last and then put in 'arg'
     * which contains the new line for the history.
     *
     */

    register i;
    FILE *tv,*get_temp();

    /* Get a temporary file. */
    tv=get_temp();

    /* Put in the lines we still want. */
    for (i=count-1;i>=0;i--){
        if (i!=except){
            fprintf(tv,"%s\n",hist[i]);
        }
    }

    /* Put in the new line from 'arg'. */
    fprintf(tv,"%s\n",arg);

    /* Rename the temporary to be the new history file. */
    close_temp(tv);
}



normal(string)
char *string;
{
    /*
     * A normal filename was found, put it into arg. First of all if there
     * is a history and the file is already in it (which means they could
     * have gotten to this file in other ways), then reconstruct the history
     * as though they had. Also offer spelling help.
     *
     */

    register count;
    register i;

    /* Put it into 'arg'. */
    sprintf(arg,"%s",string);

    /* If there is a history file. */
    if (got_vi()){

        /* Read it and split it up. */
        read_hist();
        count=split_hist();

        /* If it is in the history then reconstruct and return. */
        for (i=0;i<count;i++){
            if (!strcmp(hist[i],arg)){
                reconstruct(i,count);
                return;
            }
        }

        /* It's not in the history, help with spelling then reconstruct. */
        if (!spell_help()){
            find();
        }

        /* If it is in the history then reconstruct and return. */
        for (i=0;i<count;i++){
            if (!strcmp(hist[i],arg)){
                reconstruct(i,count);
                return;
            }
        }

        reconstruct(HIST_LINES,count);
    }
    else{

        /*
         * There is no history around so help with spelling and set up a
         * history for next time.
         *
         */

        if (!spell_help()){
            find();
        }
        new_vi();
    }

}



multiple(number,args,size)
int number;
char **args;
{
    /*
     * There were several names on the command line so we just strcat them
     * into the 'arg' array. Check to see that the length of all the args
     * will not be greater than "size" or else we will overflow arg.
     *
     * The total argument length must be at most size-1 characters, including
     * spaces. arg needs to have a trailing '\0' so that do_vi() wont break.
     *
     */

    register count;
    register i;
    register total=0;

    *arg='\0';
    while (--number){
        if ((total+=strlen(*(args+1)))>=size){

            /*
             * If you are running e and you find that this condition occurs,
             * the solution is to simply increase the value of the #define
             * line for ARG_CHARS in e.h.
             *
             */

            fprintf(stderr,
            "%c%c%cWarning! Argument list too long, truncated after \"%s\".\n",
                BELL,BELL,BELL,*args);
            sleep(2);   /* Give them some chance to see what happened. */
            break;
        }

        strcat(arg,*++args);
        if (number>1){
            strcat(arg," ");

            /*
             * Add one to total for the space. There's no need to check for
             * overflow here as we know there is another argument since
             * number > 1 still. Thus if this overflows arg, then it is going
             * to be caught anyway in the test at the top of the while loop.
             *
             */

            total++;
        }
    }

    /*
     * Now if there is a history file and we can find an identical line
     * then reconstruct with that line at the bottom.
     *
     */

    if (got_vi()){
        read_hist();
        count=split_hist();
        for (i=0;i<count;i++){
            if (!strcmp(hist[i],arg)){
                reconstruct(i,count);
                return;
            }
        }

        /*
         * Rebuild, including everything but the counth last (i.e. make
         * a new history by omitting the oldest file in the current one and
         * putting 'arg' on the end.
         *
         */

        reconstruct(HIST_LINES,count);
    }
    else{
        /* There was no history file so try to give them one for next time. */
        new_vi();
    }
}



got_vi()
{
    /* Indicate if there is a history file that they own or otherwise. */
    struct stat buf;

    if (stat(HIST,&buf)==-1){
        return(0);
    }
    else{
        return(getuid()==buf.st_uid);
    }
}



new_vi()
{
    /*
     * Attempt to make a new history file.
     * During which several things could go wrong.
     *
     */

    FILE *vh,*fopen(),*fclose();
    struct stat buf;

    /* If you can't read the current directory, get out. */
    if (stat(".",&buf)==-1){
        e_error("%s \".\"","Could not stat");
    }

    /* If you own the directory (you can't get a history in /tmp). */
    if (getuid()==buf.st_uid){

        /* If we can't make a history, get out. */
        if ((vh=fopen(HIST,"w"))==NULL){
            e_error("%s %s %s","Could not open",HIST,"for writing.");
        }

        /* Put in the 'arg' that we will be vi'ing in a second. */
        fprintf(vh,"%s\n",arg);

        /* Close the history. */
        if (fclose(vh)==(FILE *)EOF){
            e_error("%s %s","Could not close",HIST);
        }

        /* Give the history some protection - for those who want it! */
        if (chmod(HIST,E_MODE)==-1){
            e_error("%s %s","Could not chmod",HIST);
        }
    }
}




spell_help()
{
    /*
       Unashamedly stolen (and modified) from "The UNIX Programming
       Environment" - Kernighan and Pike.

       Read the directory and if the file they want (in 'arg') does not
       exist then see if there is one that does that has similar spelling
       to what they requested. Offer the change and handle the reply.
    */

    register dist;
    DIR *dp, *opendir();
    struct direct *readdir();
    struct direct *entry;
    register len;
    struct stat buf;
    int ch;

    /* If the file already exists just return - they don't need help. */
    if (stat(arg,&buf)==0){
        return(1);
    }

    /* If the current directory can't be read then return. */
    if ((dp=opendir("."))==NULL){
        return(0);
    }

    /* Get the length of what we are seeking to cut down on strcmping time. */
    len=strlen(arg);

    for (entry=readdir(dp);entry!=NULL;entry=readdir(dp)){

        register int dlen=entry->d_namlen;

        /* Try to stat the entry. */
        if (stat(entry->d_name,&buf)==-1){
            continue;
        }

        /* If it's not a regular file then continue. */
        if ((buf.st_mode&S_IFMT)!=S_IFREG){
            continue;
        }

        /*
         * If this entry has
         *
         *      length == sought length +/- 1
         *
         * then it should be checked.
         *
         */

        if (entry->d_ino && dlen>=len-1 && dlen<=len+1){

            /*
             * If the distance between this name and the one the user enetered
             * is too great then just continue.
             *
             */

            if (sp_dist(entry->d_name,arg)==3) continue;


            /* Otherwise offer them this one. */
            terminal(TERM_SET);
            fprintf(stderr,"correct to %s [y]? ",entry->d_name);

            /* Get and process the reply. */

            ch=getc(stdin);
            terminal(TERM_RESET);

            if (ch=='N'){

                /* No, and they mean it. Offer no more help. */
                fprintf(stderr,"No!\n");
                break;
            }

            else if (ch=='n'){

                /* No, but they'd like more help. */
                fprintf(stderr,"no\n");
                continue;
            }

            else if (ch=='q'||ch=='Q'||ch==(int)erase){

                /* Quit. */
                fprintf(stderr,"quit\n");
                closedir(dp);
                exit(0);
            }

            else{

                /* Yes. */
                fprintf(stderr,"yes\n");
                closedir(dp);
                strcpy(arg,entry->d_name);
                return(1);
            }
        }
    }

    closedir(dp);
    return(0);
}



sp_dist(s,t)
char *s;
char *t;
{
    /*
     * Stolen from the same place as spell_help() above.

     * Work out the distance between the strings 's' and 't' according
     * to the rough metric that
     *
     *     Identical = 0
     *     Interchanged characters = 1
     *     Wrong character/extra character/missing character = 2
     *     Forget it = 3
     *
     */

    while (*s++==*t){
        if (*t++=='\0'){
            /* identical */
            return(0);
        }
    }

    if (*--s){
        if (*t){
            if (s[1]&&t[1]&&*s==t[1]&&*t==s[1]&&!strcmp(s+2,t+2)){
                /* Interchanged chars. */
                return(1);
            }
            if (!strcmp(s+1,t+1)){
                /* Wrong char. */
                return(2);
            }
        }
        if (!strcmp(s+1,t)){
            /* Extra char in 't'. */
            return(2);
        }
    }
    if (!strcmp(s,t+1)){
        /* Extra char in 's'. */
        return(2);
    }

    /* Forget it. */
    return(3);
}




find()
{
    /*
     * This takes the environment variable which is #defined as PATH and
     * extracts the directory names from it. They may be separated by
     * arbitrary numbers of delimiter characters (currently "\n", "\t", " "
     * and ":"). Each directory is then checked to see if it contains the
     * desired filename (with a call to check). Spelling corrections are
     * not attempted.
     *
     */

    extern char *getwd();
    extern char *getenv();
    char *p;
    char path[MAX_PATH];
    char *dir;
    char *space;
    char *current_dir;
    char wd[MAXPATHLEN];
    char what[ARG_CHARS];

    if (!(p=getenv(E_PATH))) return;

    if (strlen(p)>=MAX_PATH){
        e_error("%s %s %s %d.","Length of",E_PATH,"variable exceeds",MAX_PATH);
    }

    strcpy(path,p);
    strcpy(what,arg);

    if (!(current_dir=getwd(wd))){
        e_error("%s","Could not get working directory.");
    }

    dir=path;

    /* Skip initial delimiters in the PATH variable. */
    while (*dir && is_delim(dir)) dir++;

    if (!*dir) return(0);   /* There was nothing there but delimiters! */

    space=dir+1;

    while (*space){

        /* Move "space" along to the first non delimiter. */
        while (*space && !is_delim(space)) space++;

        if (*space){
            *space='\0';
            space++;
        }

        /* Skip any white space between directory names. */
        while (*space && is_delim(space)) space++;

        /* Check the directory "dir" for the filename "what". */
        if (check(what,dir)){

            /* Offer them dir/what. */
            terminal(TERM_SET);
            fprintf(stderr,"%s/%s [y]? ",dir,what);

            /* Process the reply. */
            switch (getc(stdin)){
                case 'N':
                case 'n':{
                    fprintf(stderr,"no\n");
                    terminal(TERM_RESET);
                    break;
                }

                case 'q':
                case 'Q':{
                    fprintf(stderr,"quit\n");
                    terminal(TERM_RESET);
                    exit(0);
                    break;
                }

                default :{
                    fprintf(stderr,"yes\n");
                    terminal(TERM_RESET);
                    if (chdir(current_dir)==-1){
                        e_error("%s %s","Could not chdir to",current_dir);
                    }
                    sprintf(arg,"%s/%s",dir,what);
                    return(1);
                }
            }
        }
        dir=space;
    }

    /* Go back to the original directory. */
    if (chdir(current_dir)==-1){
        e_error("%s %s","Could not chdir to",current_dir);
    }
    return(0);
}



check(target,dir)
char *target;
char *dir;
{
    /*
     * Checks to see if the name "target" can be found in the directory "dir".
     *
     */

    DIR *dp, *opendir();
    struct direct *readdir();
    struct direct *entry;
    struct stat buf;

    if ((dp=opendir(dir))==NULL){
        fprintf(stderr,"Cannot open \"%s\"\n",dir);
        return(0);
    }

    for (entry=readdir(dp);entry!=NULL;entry=readdir(dp)){
        if (!strcmp(entry->d_name,target)){
            if (chdir(dir)==-1){
                perror("chdir");
                return(0);
            }

            if (stat(entry->d_name,&buf)==-1){
                /*
                 * At this point I used to have perror() give a message and
                 * the function return. Then one day e ran across an unresolved
                 * symbolic link at this point. The filename existed in the
                 * search directory, but it could not be stat'd as the thing
                 * it was supposedly linked to had been removed.
                 *
                 * The easiest thing (I think) to do is to ignore it.
                 */

                fprintf(stderr,
                    "%c%c%cWarning: Suspected unresolved symbolic link %s/%s\n",
                    BELL,BELL,BELL,dir,entry->d_name);
                sleep(2);
                continue;
            }

            /*
                If it is not a directory and EITHER you own it and can
                read it OR you don't own it and it is readable by others,
                OR you are in the group of the owner and it's group readable
                    - then this is it.
            */

            if (    ((buf.st_mode&S_IFMT)==S_IFREG)  &&
                    (
                        (buf.st_uid==getuid() && buf.st_mode&S_IREAD)
                        ||
                        (buf.st_gid==getgid() && buf.st_mode&G_READ)
                        ||
                        (buf.st_uid!=getuid() && buf.st_mode&O_READ)
                    )
                )
            {
                return(1);
            }
        }
    }
    return(0);
}



/* VARARGS1 */
e_error(a,b,c,d,e,f)
char *a;
{
    /*
     * Print the error message, clean up and get out.
     *
     */

    fprintf(stderr,"%s: ",myname);
    fprintf(stderr,a,b,c,d,e,f);
    fputc('\n',stderr);
    terminal(TERM_RESET);
    unlink(tmp_file);
    exit(1);
}
@//E*O*F e.c//
chmod u=rw,g=rx,o=rx e.c

echo Inspecting for damage in transit...
temp=/tmp/shar$$; dtemp=/tmp/.shar$$
trap "rm -f $temp $dtemp; exit" 0 1 2 3 15
cat > $temp <<\!!!
      56     254    1791 README
     192     890    6788 e.cat
     191    1008    5781 e.1
      14      37     208 Makefile
      10      18     111 MANIFEST
      61     303    2271 MODS
     151     375    2697 e.h
    1429    3783   35152 e.c
    2104    6668   54799 total
!!!
wc  README e.cat e.1 Makefile MANIFEST MODS e.h e.c | sed 's=[^ ]*/==' | diff -b $temp - >$dtemp
if [ -s $dtemp ]
then echo "Ouch [diff of wc output]:" ; cat $dtemp
else echo "No problems found."
fi
exit 0