WebSVN – SvarDOS – Diff – /svarcom/trunk/command.c


/*
 * SvarCOM is a command-line interpreter.
 *
 * a little memory area is allocated as high as possible. it contains:
 *  - a signature (like XMS drivers do)
 *  - a routine for exec'ing programs
 *  - a "last command" buffer for input history
 *
 * when svarcom starts, it tries locating the routine in memory.
 *
 * if found:
 *   waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.
 *
 * if not found:
 *   installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine
 *   and quit.
 *
 *
 *
 * good lecture about PSP and allocating memory
 * https://retrocomputing.stackexchange.com/questions/20001/how-much-of-the-program-segment-prefix-area-can-be-reused-by-programs-with-impun/20006#20006
 *
 * PSP structure
 * http://www.piclist.com/techref/dos/psps.htm
 *
 *
 *
 * === MCB ===
 *
 * each time that DOS allocates memory, it prefixes the allocated memory with
 * a 16-bytes structure called a "Memory Control Block" (MCB). This control
 * block has the following structure:
 *
 * Offset  Size     Description
 *   00h   byte     'M' =  non-last member of the MCB chain
 *                  'Z' = indicates last entry in MCB chain
 *                  other values cause "Memory Allocation Failure" on exit
 *   01h   word     PSP segment address of the owner (Process Id)
 *                  possible values:
 *                    0 = free
 *                    8 = Allocated by DOS before first user pgm loaded
 *                    other = Process Id/PSP segment address of owner
 *   03h  word      number of paragraphs related to this MCB (excluding MCB)
 *   05h  11 bytes  reserved
 *   10h  ...       start of actual allocated memory block
 */
 
#include <i86.h>
#include <dos.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include <process.h>
 
#include "cmd.h"
#include "env.h"
#include "helpers.h"
#include "rmodinit.h"
 
struct config {
  int locate;
  int install;
  int envsiz;
} cfg;
 
 
static void parse_argv(struct config *cfg, int argc, char **argv) {
  int i;
  memset(cfg, 0, sizeof(*cfg));
 
  for (i = 1; i < argc; i++) {
    if (strcmp(argv[i], "/locate") == 0) {
      cfg->locate = 1;
    }
    if (strstartswith(argv[i], "/e:") == 0) {
      cfg->envsiz = atoi(argv[i]+3);
      if (cfg->envsiz < 64) cfg->envsiz = 0;
    }
  }
}
 
 
static void buildprompt(char *s, unsigned short envseg) {
  /* locate the prompt variable or use the default pattern */
  const char far *fmt = env_lookup(envseg, "PROMPT");
  while ((fmt != NULL) && (*fmt != 0)) {
    fmt++;
    if (fmt[-1] == '=') break;
  }
  if ((fmt == NULL) || (*fmt == 0)) fmt = "$p$g"; /* fallback to default if empty */
  /* build the prompt string based on pattern */
  for (; *fmt != 0; fmt++) {
    if (*fmt != '$') {
      *s = *fmt;
      s++;
      continue;
    }
    /* escape code ($P, etc) */
    fmt++;
    switch (*fmt) {
      case 'Q':  /* $Q = = (equal sign) */
      case 'q':
        *s = '=';
        s++;
        break;
      case '$':  /* $$ = $ (dollar sign) */
        *s = '$';
        s++;
        break;
      case 'T':  /* $t = current time */
      case 't':
        s += sprintf(s, "00:00"); /* TODO */
        break;
      case 'D':  /* $D = current date */
      case 'd':
        s += sprintf(s, "1985-07-29"); /* TODO */
        break;
      case 'P':  /* $P = current drive and path */
      case 'p':
        _asm {
          mov ah, 0x19    /* DOS 1+ - GET CURRENT DRIVE */
          int 0x21
          mov bx, s
          mov [bx], al  /* AL = drive (00 = A:, 01 = B:, etc */
        }
        *s += 'A';
        s++;
        *s = ':';
        s++;
        *s = '\\';
        s++;
        _asm {
          mov ah, 0x47    /* DOS 2+ - CWD - GET CURRENT DIRECTORY */
          xor dl,dl       /* DL = drive number (00h = default, 01h = A:, etc) */
          mov si, s       /* DS:SI -> 64-byte buffer for ASCIZ pathname */
          int 0x21
        }
        while (*s != 0) s++; /* move ptr forward to end of pathname */
        break;
      case 'V':  /* $V = DOS version number */
      case 'v':
        s += sprintf(s, "VER"); /* TODO */
        break;
      case 'N':  /* $N = current drive */
      case 'n':
        _asm {
          mov ah, 0x19    /* DOS 1+ - GET CURRENT DRIVE */
          int 0x21
          mov bx, s
          mov [bx], al  /* AL = drive (00 = A:, 01 = B:, etc */
        }
        *s += 'A';
        s++;
        break;
      case 'G':  /* $G = > (greater-than sign) */
      case 'g':
        *s = '>';
        s++;
        break;
      case 'L':  /* $L = < (less-than sign) */
      case 'l':
        *s = '<';
        s++;
        break;
      case 'B':  /* $B = | (pipe) */
      case 'b':
        *s = '|';
        s++;
        break;
      case 'H':  /* $H = backspace (erases previous character) */
      case 'h':
        *s = '\b';
        s++;
        break;
      case 'E':  /* $E = Escape code (ASCII 27) */
      case 'e':
        *s = 27;
        s++;
        break;
      case '_':  /* $_ = CR+LF */
        *s = '\r';
        s++;
        *s = '\n';
        s++;
        break;
    }
  }
  *s = '$';
}
 
 
static void run_as_external(const char far *cmdline) {
  char buff[256];
  char const *argvlist[256];
  int i, n;
  /* copy buffer to a near var (incl. trailing CR), insert a space before
     every slash to make sure arguments are well separated */
  n = 0;
  i = 0;
  for (;;) {
    if (cmdline[i] == '/') buff[n++] = ' ';
    buff[n++] = cmdline[i++];
    if (buff[n] == 0) break;
  }
 
  cmd_explode(buff, cmdline, argvlist);
 
  /* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */
 
  /* must be an external command then. this call should never return, unless
   * the other program failed to be executed. */
  execvp(argvlist[0], argvlist);
}
 
 
static void set_comspec_to_self(unsigned short envseg) {
  unsigned short *psp_envseg = (void *)(0x2c); /* pointer to my env segment field in the PSP */
  char far *myenv = MK_FP(*psp_envseg, 0);
  unsigned short varcount;
  char buff[256] = "COMSPEC=";
  char *buffptr = buff + 8;
  /* who am i? look into my own environment, at the end of it should be my EXEPATH string */
  while (*myenv != 0) {
    /* consume a NULL-terminated string */
    while (*myenv != 0) myenv++;
    /* move to next string */
    myenv++;
  }
  /* get next word, if 1 then EXEPATH follows */
  myenv++;
  varcount = *myenv;
  myenv++;
  varcount |= (*myenv << 8);
  myenv++;
  if (varcount != 1) return; /* NO EXEPATH FOUND */
  while (*myenv != 0) {
    *buffptr = *myenv;
    buffptr++;
    myenv++;
  }
  *buffptr = 0;
  /* printf("EXEPATH: '%s'\r\n", buff); */
  env_setvar(envseg, buff);
}
 
 
int main(int argc, char **argv) {
  static struct config cfg;
  static unsigned short rmod_seg;
  static unsigned short far *rmod_envseg;
  static unsigned short far *lastexitcode;
  static unsigned char BUFFER[4096];
 
  parse_argv(&cfg, argc, argv);
 
  rmod_seg = rmod_find();
  if (rmod_seg == 0xffff) {
    rmod_seg = rmod_install(cfg.envsiz);
    if (rmod_seg == 0xffff) {
      outputnl("ERROR: rmod_install() failed");
      return(1);
    }
/*    printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */
  } else {
/*    printf("rmod found at seg 0x%04x\r\n", rmod_seg); */
  }
 
  rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);
  lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);
 
  /* make COMPSEC point to myself */
  set_comspec_to_self(*rmod_envseg);
 
/*  {
    unsigned short envsiz;
    unsigned short far *sizptr = MK_FP(*rmod_envseg - 1, 3);
    envsiz = *sizptr;
    envsiz *= 16;
    printf("rmod_inpbuff at %04X:%04X, env_seg at %04X:0000 (env_size = %u bytes)\r\n", rmod_seg, RMOD_OFFSET_INPBUFF, *rmod_envseg, envsiz);
  }*/
 
  for (;;) {
    char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);
 
    /* revert input history terminator to \r */
    if (cmdline[-1] != 0) {
      cmdline[(unsigned short)(cmdline[-1])] = '\r';
    }
 
    {
      /* print shell prompt */
      char *promptptr = BUFFER;
      buildprompt(promptptr, *rmod_envseg);
      _asm {
        push ax
        push dx
        mov ah, 0x09
        mov dx, promptptr
        int 0x21
        pop dx
        pop ax
      }
    }
 
    /* wait for user input */
    _asm {
      push ax
      push bx
      push cx
      push dx
      push ds
 
      /* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */
      mov ax, 0x4800
      int 0x2f
      mov bl, al /* save doskey status in BL */
 
      /* set up buffered input */
      mov ax, rmod_seg
      push ax
      pop ds
      mov dx, RMOD_OFFSET_INPBUFF
 
      /* execute either DOS input or DOSKEY */
      test bl, bl /* zf set if no DOSKEY present */
      jnz DOSKEY
 
      mov ah, 0x0a
      int 0x21
      jmp short DONE
 
      DOSKEY:
      mov ax, 0x4810
      int 0x2f
 
      DONE:
      pop ds
      pop dx
      pop cx
      pop bx
      pop ax
    }
    outputnl("");
 
    /* if nothing entered, loop again */
    if (cmdline[-1] == 0) continue;
 
    /* replace \r by a zero terminator */
    cmdline[(unsigned char)(cmdline[-1])] = 0;
 
    /* move pointer forward to skip over any leading spaces */
    while (*cmdline == ' ') cmdline++;
 
    /* update rmod's ptr to COMPSPEC so it is always up to date */
    rmod_updatecomspecptr(rmod_seg, *rmod_envseg);
 
    /* try matching (and executing) an internal command */
    {
      int ecode = cmd_process(*rmod_envseg, cmdline, BUFFER);
      if (ecode >= 0) *lastexitcode = ecode;
      if (ecode >= -1) { /* internal command executed */
        outputnl("");
        continue;
      }
    }
 
    /* if here, then this was not an internal command */
    run_as_external(cmdline);
 
    /* execvp() replaces the current process by the new one
    if I am still alive then external command failed to execute */
    outputnl("Bad command or file name");
 
  }
 
  return(0);
}
 

Rev 377	Rev 397
1	`/*`	1	`/*`
2	`* SvarCOM is a command-line interpreter.`	2	`* SvarCOM is a command-line interpreter.`
3	`*`	3	`*`
4	`* a little memory area is allocated as high as possible. it contains:`	4	`* a little memory area is allocated as high as possible. it contains:`
5	`* - a signature (like XMS drivers do)`	5	`* - a signature (like XMS drivers do)`
6	`* - a routine for exec'ing programs`	6	`* - a routine for exec'ing programs`
7	`* - a "last command" buffer for input history`	7	`* - a "last command" buffer for input history`
8	`*`	8	`*`
9	`* when svarcom starts, it tries locating the routine in memory.`	9	`* when svarcom starts, it tries locating the routine in memory.`
10	`*`	10	`*`
11	`* if found:`	11	`* if found:`
12	`* waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.`	12	`* waits for user input and processes it. if execing something is required, set the "next exec" field in routine's memory and quit.`
13	`*`	13	`*`
14	`* if not found:`	14	`* if not found:`
15	`* installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine`	15	`* installs it by creating a new PSP, set int 22 vector to the routine, set my "parent PSP" to the routine`
16	`* and quit.`	16	`* and quit.`
17	`*`	17	`*`
18	`*`	18	`*`
19	`*`	19	`*`
20	`* good lecture about PSP and allocating memory`	20	`* good lecture about PSP and allocating memory`
21	`* https://retrocomputing.stackexchange.com/questions/20001/how-much-of-the-program-segment-prefix-area-can-be-reused-by-programs-with-impun/20006#20006`	21	`* https://retrocomputing.stackexchange.com/questions/20001/how-much-of-the-program-segment-prefix-area-can-be-reused-by-programs-with-impun/20006#20006`
22	`*`	22	`*`
23	`* PSP structure`	23	`* PSP structure`
24	`* http://www.piclist.com/techref/dos/psps.htm`	24	`* http://www.piclist.com/techref/dos/psps.htm`
25	`*`	25	`*`
26	`*`	26	`*`
27	`*`	27	`*`
28	`* === MCB ===`	28	`* === MCB ===`
29	`*`	29	`*`
30	`* each time that DOS allocates memory, it prefixes the allocated memory with`	30	`* each time that DOS allocates memory, it prefixes the allocated memory with`
31	`* a 16-bytes structure called a "Memory Control Block" (MCB). This control`	31	`* a 16-bytes structure called a "Memory Control Block" (MCB). This control`
32	`* block has the following structure:`	32	`* block has the following structure:`
33	`*`	33	`*`
34	`* Offset Size Description`	34	`* Offset Size Description`
35	`* 00h byte 'M' = non-last member of the MCB chain`	35	`* 00h byte 'M' = non-last member of the MCB chain`
36	`* 'Z' = indicates last entry in MCB chain`	36	`* 'Z' = indicates last entry in MCB chain`
37	`* other values cause "Memory Allocation Failure" on exit`	37	`* other values cause "Memory Allocation Failure" on exit`
38	`* 01h word PSP segment address of the owner (Process Id)`	38	`* 01h word PSP segment address of the owner (Process Id)`
39	`* possible values:`	39	`* possible values:`
40	`* 0 = free`	40	`* 0 = free`
41	`* 8 = Allocated by DOS before first user pgm loaded`	41	`* 8 = Allocated by DOS before first user pgm loaded`
42	`* other = Process Id/PSP segment address of owner`	42	`* other = Process Id/PSP segment address of owner`
43	`* 03h word number of paragraphs related to this MCB (excluding MCB)`	43	`* 03h word number of paragraphs related to this MCB (excluding MCB)`
44	`* 05h 11 bytes reserved`	44	`* 05h 11 bytes reserved`
45	`* 10h ... start of actual allocated memory block`	45	`* 10h ... start of actual allocated memory block`
46	`*/`	46	`*/`
47		47
48	`#include <i86.h>`	48	`#include <i86.h>`
49	`#include <dos.h>`	49	`#include <dos.h>`
50	`#include <stdio.h>`	50	`#include <stdio.h>`
51	`#include <stdlib.h>`	51	`#include <stdlib.h>`
52	`#include <string.h>`	52	`#include <string.h>`
53		53
54	`#include <process.h>`	54	`#include <process.h>`
55		55
56	`#include "cmd.h"`	56	`#include "cmd.h"`
57	`#include "env.h"`	57	`#include "env.h"`
58	`#include "helpers.h"`	58	`#include "helpers.h"`
59	`#include "rmodinit.h"`	59	`#include "rmodinit.h"`
60		60
61	`struct config {`	61	`struct config {`
62	`int locate;`	62	`int locate;`
63	`int install;`	63	`int install;`
64	`int envsiz;`	64	`int envsiz;`
65	`} cfg;`	65	`} cfg;`
66		66
67		67
68	`static void parse_argv(struct config cfg, int argc, char *argv) {`	68	`static void parse_argv(struct config cfg, int argc, char *argv) {`
69	`int i;`	69	`int i;`
70	`memset(cfg, 0, sizeof(*cfg));`	70	`memset(cfg, 0, sizeof(*cfg));`
71		71
72	`for (i = 1; i < argc; i++) {`	72	`for (i = 1; i < argc; i++) {`
73	`if (strcmp(argv[i], "/locate") == 0) {`	73	`if (strcmp(argv[i], "/locate") == 0) {`
74	`cfg->locate = 1;`	74	`cfg->locate = 1;`
75	`}`	75	`}`
76	`if (strstartswith(argv[i], "/e:") == 0) {`	76	`if (strstartswith(argv[i], "/e:") == 0) {`
77	`cfg->envsiz = atoi(argv[i]+3);`	77	`cfg->envsiz = atoi(argv[i]+3);`
78	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	78	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
79	`}`	79	`}`
80	`}`	80	`}`
81	`}`	81	`}`
82		82
83		83
84	`static void buildprompt(char *s, unsigned short envseg) {`	84	`static void buildprompt(char *s, unsigned short envseg) {`
85	`/* locate the prompt variable or use the default pattern */`	85	`/* locate the prompt variable or use the default pattern */`
86	`const char far *fmt = env_lookup(envseg, "PROMPT");`	86	`const char far *fmt = env_lookup(envseg, "PROMPT");`
87	`while ((fmt != NULL) && (*fmt != 0)) {`	87	`while ((fmt != NULL) && (*fmt != 0)) {`
88	`fmt++;`	88	`fmt++;`
89	`if (fmt[-1] == '=') break;`	89	`if (fmt[-1] == '=') break;`
90	`}`	90	`}`
91	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	91	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
92	`/* build the prompt string based on pattern */`	92	`/* build the prompt string based on pattern */`
93	`for (; *fmt != 0; fmt++) {`	93	`for (; *fmt != 0; fmt++) {`
94	`if (*fmt != '$') {`	94	`if (*fmt != '$') {`
95	`s = fmt;`	95	`s = fmt;`
96	`s++;`	96	`s++;`
97	`continue;`	97	`continue;`
98	`}`	98	`}`
99	`/* escape code ($P, etc) */`	99	`/* escape code ($P, etc) */`
100	`fmt++;`	100	`fmt++;`
101	`switch (*fmt) {`	101	`switch (*fmt) {`
102	`case 'Q': /* $Q = = (equal sign) */`	102	`case 'Q': /* $Q = = (equal sign) */`
103	`case 'q':`	103	`case 'q':`
104	`*s = '=';`	104	`*s = '=';`
105	`s++;`	105	`s++;`
106	`break;`	106	`break;`
107	`case '$': /* $$ = $ (dollar sign) */`	107	`case '$': /* $$ = $ (dollar sign) */`
108	`*s = '$';`	108	`*s = '$';`
109	`s++;`	109	`s++;`
110	`break;`	110	`break;`
111	`case 'T': /* $t = current time */`	111	`case 'T': /* $t = current time */`
112	`case 't':`	112	`case 't':`
113	`s += sprintf(s, "00:00"); /* TODO */`	113	`s += sprintf(s, "00:00"); /* TODO */`
114	`break;`	114	`break;`
115	`case 'D': /* $D = current date */`	115	`case 'D': /* $D = current date */`
116	`case 'd':`	116	`case 'd':`
117	`s += sprintf(s, "1985-07-29"); /* TODO */`	117	`s += sprintf(s, "1985-07-29"); /* TODO */`
118	`break;`	118	`break;`
119	`case 'P': /* $P = current drive and path */`	119	`case 'P': /* $P = current drive and path */`
120	`case 'p':`	120	`case 'p':`
121	`_asm {`	121	`_asm {`
122	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	122	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
123	`int 0x21`	123	`int 0x21`
124	`mov bx, s`	124	`mov bx, s`
125	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	125	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
126	`}`	126	`}`
127	`*s += 'A';`	127	`*s += 'A';`
128	`s++;`	128	`s++;`
129	`*s = ':';`	129	`*s = ':';`
130	`s++;`	130	`s++;`
131	`*s = '\\';`	131	`*s = '\\';`
132	`s++;`	132	`s++;`
133	`_asm {`	133	`_asm {`
134	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	134	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
135	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	135	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
136	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	136	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
137	`int 0x21`	137	`int 0x21`
138	`}`	138	`}`
139	`while (s != 0) s++; / move ptr forward to end of pathname */`	139	`while (s != 0) s++; / move ptr forward to end of pathname */`
140	`break;`	140	`break;`
141	`case 'V': /* $V = DOS version number */`	141	`case 'V': /* $V = DOS version number */`
142	`case 'v':`	142	`case 'v':`
143	`s += sprintf(s, "VER"); /* TODO */`	143	`s += sprintf(s, "VER"); /* TODO */`
144	`break;`	144	`break;`
145	`case 'N': /* $N = current drive */`	145	`case 'N': /* $N = current drive */`
146	`case 'n':`	146	`case 'n':`
147	`_asm {`	147	`_asm {`
148	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	148	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
149	`int 0x21`	149	`int 0x21`
150	`mov bx, s`	150	`mov bx, s`
151	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	151	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
152	`}`	152	`}`
153	`*s += 'A';`	153	`*s += 'A';`
154	`s++;`	154	`s++;`
155	`break;`	155	`break;`
156	`case 'G': /* $G = > (greater-than sign) */`	156	`case 'G': /* $G = > (greater-than sign) */`
157	`case 'g':`	157	`case 'g':`
158	`*s = '>';`	158	`*s = '>';`
159	`s++;`	159	`s++;`
160	`break;`	160	`break;`
161	`case 'L': /* $L = < (less-than sign) */`	161	`case 'L': /* $L = < (less-than sign) */`
162	`case 'l':`	162	`case 'l':`
163	`*s = '<';`	163	`*s = '<';`
164	`s++;`	164	`s++;`
165	`break;`	165	`break;`
166	`case 'B': /* $B = \| (pipe) */`	166	`case 'B': /* $B = \| (pipe) */`
167	`case 'b':`	167	`case 'b':`
168	`*s = '\|';`	168	`*s = '\|';`
169	`s++;`	169	`s++;`
170	`break;`	170	`break;`
171	`case 'H': /* $H = backspace (erases previous character) */`	171	`case 'H': /* $H = backspace (erases previous character) */`
172	`case 'h':`	172	`case 'h':`
173	`*s = '\b';`	173	`*s = '\b';`
174	`s++;`	174	`s++;`
175	`break;`	175	`break;`
176	`case 'E': /* $E = Escape code (ASCII 27) */`	176	`case 'E': /* $E = Escape code (ASCII 27) */`
177	`case 'e':`	177	`case 'e':`
178	`*s = 27;`	178	`*s = 27;`
179	`s++;`	179	`s++;`
180	`break;`	180	`break;`
181	`case '_': /* $_ = CR+LF */`	181	`case '_': /* $_ = CR+LF */`
182	`*s = '\r';`	182	`*s = '\r';`
183	`s++;`	183	`s++;`
184	`*s = '\n';`	184	`*s = '\n';`
185	`s++;`	185	`s++;`
186	`break;`	186	`break;`
187	`}`	187	`}`
188	`}`	188	`}`
189	`*s = '$';`	189	`*s = '$';`
190	`}`	190	`}`
191		191
192		192
193	`static void run_as_external(const char far *cmdline) {`	193	`static void run_as_external(const char far *cmdline) {`
194	`char buff[256];`	194	`char buff[256];`
195	`char const *argvlist[256];`	195	`char const *argvlist[256];`
196	`int i, n;`	196	`int i, n;`
197	`/* copy buffer to a near var (incl. trailing CR), insert a space before`	197	`/* copy buffer to a near var (incl. trailing CR), insert a space before`
198	`every slash to make sure arguments are well separated */`	198	`every slash to make sure arguments are well separated */`
199	`n = 0;`	199	`n = 0;`
200	`i = 0;`	200	`i = 0;`
201	`for (;;) {`	201	`for (;;) {`
202	`if (cmdline[i] == '/') buff[n++] = ' ';`	202	`if (cmdline[i] == '/') buff[n++] = ' ';`
203	`buff[n++] = cmdline[i++];`	203	`buff[n++] = cmdline[i++];`
204	`if (buff[n] == 0) break;`	204	`if (buff[n] == 0) break;`
205	`}`	205	`}`
206		206
207	`cmd_explode(buff, cmdline, argvlist);`	207	`cmd_explode(buff, cmdline, argvlist);`
208		208
209	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`	209	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`
210		210
211	`/* must be an external command then. this call should never return, unless`	211	`/* must be an external command then. this call should never return, unless`
212	`* the other program failed to be executed. */`	212	`* the other program failed to be executed. */`
213	`execvp(argvlist[0], argvlist);`	213	`execvp(argvlist[0], argvlist);`
214	`}`	214	`}`
215		215
216		216
217	`static void set_comspec_to_self(unsigned short envseg) {`	217	`static void set_comspec_to_self(unsigned short envseg) {`
218	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	218	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
219	`char far myenv = MK_FP(psp_envseg, 0);`	219	`char far myenv = MK_FP(psp_envseg, 0);`
220	`unsigned short varcount;`	220	`unsigned short varcount;`
221	`char buff[256] = "COMSPEC=";`	221	`char buff[256] = "COMSPEC=";`
222	`char *buffptr = buff + 8;`	222	`char *buffptr = buff + 8;`
223	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	223	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
224	`while (*myenv != 0) {`	224	`while (*myenv != 0) {`
225	`/* consume a NULL-terminated string */`	225	`/* consume a NULL-terminated string */`
226	`while (*myenv != 0) myenv++;`	226	`while (*myenv != 0) myenv++;`
227	`/* move to next string */`	227	`/* move to next string */`
228	`myenv++;`	228	`myenv++;`
229	`}`	229	`}`
230	`/* get next word, if 1 then EXEPATH follows */`	230	`/* get next word, if 1 then EXEPATH follows */`
231	`myenv++;`	231	`myenv++;`
232	`varcount = *myenv;`	232	`varcount = *myenv;`
233	`myenv++;`	233	`myenv++;`
234	`varcount \|= (*myenv << 8);`	234	`varcount \|= (*myenv << 8);`
235	`myenv++;`	235	`myenv++;`
236	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	236	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
237	`while (*myenv != 0) {`	237	`while (*myenv != 0) {`
238	`buffptr = myenv;`	238	`buffptr = myenv;`
239	`buffptr++;`	239	`buffptr++;`
240	`myenv++;`	240	`myenv++;`
241	`}`	241	`}`
242	`*buffptr = 0;`	242	`*buffptr = 0;`
243	`/* printf("EXEPATH: '%s'\r\n", buff); */`	243	`/* printf("EXEPATH: '%s'\r\n", buff); */`
244	`env_setvar(envseg, buff);`	244	`env_setvar(envseg, buff);`
245	`}`	245	`}`
246		246
247		247
248	`int main(int argc, char **argv) {`	248	`int main(int argc, char **argv) {`
249	`static struct config cfg;`	249	`static struct config cfg;`
250	`static unsigned short rmod_seg;`	250	`static unsigned short rmod_seg;`
251	`static unsigned short far *rmod_envseg;`	251	`static unsigned short far *rmod_envseg;`
252	`static unsigned short far *lastexitcode;`	252	`static unsigned short far *lastexitcode;`
253	`static unsigned char BUFFER[4096];`	253	`static unsigned char BUFFER[4096];`
254		254
255	`parse_argv(&cfg, argc, argv);`	255	`parse_argv(&cfg, argc, argv);`
256		256
257	`rmod_seg = rmod_find();`	257	`rmod_seg = rmod_find();`
258	`if (rmod_seg == 0xffff) {`	258	`if (rmod_seg == 0xffff) {`
259	`rmod_seg = rmod_install(cfg.envsiz);`	259	`rmod_seg = rmod_install(cfg.envsiz);`
260	`if (rmod_seg == 0xffff) {`	260	`if (rmod_seg == 0xffff) {`
261	`outputnl("ERROR: rmod_install() failed");`	261	`outputnl("ERROR: rmod_install() failed");`
262	`return(1);`	262	`return(1);`
263	`}`	263	`}`
264	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`	264	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`
265	`} else {`	265	`} else {`
266	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`	266	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`
267	`}`	267	`}`
268		268
269	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`	269	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`
270	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`	270	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`
271		271
272	`/* make COMPSEC point to myself */`	272	`/* make COMPSEC point to myself */`
273	`set_comspec_to_self(*rmod_envseg);`	273	`set_comspec_to_self(*rmod_envseg);`
274		274
275	`/* {`	275	`/* {`
276	`unsigned short envsiz;`	276	`unsigned short envsiz;`
277	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`	277	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`
278	`envsiz = *sizptr;`	278	`envsiz = *sizptr;`
279	`envsiz *= 16;`	279	`envsiz *= 16;`
280	`printf("rmod_inpbuff at %04X:%04X, env_seg at %04X:0000 (env_size = %u bytes)\r\n", rmod_seg, RMOD_OFFSET_INPBUFF, *rmod_envseg, envsiz);`	280	`printf("rmod_inpbuff at %04X:%04X, env_seg at %04X:0000 (env_size = %u bytes)\r\n", rmod_seg, RMOD_OFFSET_INPBUFF, *rmod_envseg, envsiz);`
281	`}*/`	281	`}*/`
282		282
283	`for (;;) {`	283	`for (;;) {`
284	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`	284	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`
285		285
286	`/* revert input history terminator to \r */`	286	`/* revert input history terminator to \r */`
287	`if (cmdline[-1] != 0) {`	287	`if (cmdline[-1] != 0) {`
288	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`	288	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`
289	`}`	289	`}`
290		290
291	`{`	291	`{`
292	`/* print shell prompt */`	292	`/* print shell prompt */`
293	`char *promptptr = BUFFER;`	293	`char *promptptr = BUFFER;`
294	`buildprompt(promptptr, *rmod_envseg);`	294	`buildprompt(promptptr, *rmod_envseg);`
295	`_asm {`	295	`_asm {`
296	`push ax`	296	`push ax`
297	`push dx`	297	`push dx`
298	`mov ah, 0x09`	298	`mov ah, 0x09`
299	`mov dx, promptptr`	299	`mov dx, promptptr`
300	`int 0x21`	300	`int 0x21`
301	`pop dx`	301	`pop dx`
302	`pop ax`	302	`pop ax`
303	`}`	303	`}`
304	`}`	304	`}`
305		305
306	`/* wait for user input */`	306	`/* wait for user input */`
307	`_asm {`	307	`_asm {`
308	`push ax`	308	`push ax`
309	`push bx`	309	`push bx`
310	`push cx`	310	`push cx`
311	`push dx`	311	`push dx`
312	`push ds`	312	`push ds`
313		313
314	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`	314	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`
315	`mov ax, 0x4800`	315	`mov ax, 0x4800`
316	`int 0x2f`	316	`int 0x2f`
317	`mov bl, al /* save doskey status in BL */`	317	`mov bl, al /* save doskey status in BL */`
318		318
319	`/* set up buffered input */`	319	`/* set up buffered input */`
320	`mov ax, rmod_seg`	320	`mov ax, rmod_seg`
321	`push ax`	321	`push ax`
322	`pop ds`	322	`pop ds`
323	`mov dx, RMOD_OFFSET_INPBUFF`	323	`mov dx, RMOD_OFFSET_INPBUFF`
324		324
325	`/* execute either DOS input or DOSKEY */`	325	`/* execute either DOS input or DOSKEY */`
326	`test bl, bl /* zf set if no DOSKEY present */`	326	`test bl, bl /* zf set if no DOSKEY present */`
327	`jnz DOSKEY`	327	`jnz DOSKEY`
328		328
329	`mov ah, 0x0a`	329	`mov ah, 0x0a`
330	`int 0x21`	330	`int 0x21`
331	`jmp short DONE`	331	`jmp short DONE`
332		332
333	`DOSKEY:`	333	`DOSKEY:`
334	`mov ax, 0x4810`	334	`mov ax, 0x4810`
335	`int 0x2f`	335	`int 0x2f`
336		336
337	`DONE:`	337	`DONE:`
338	`pop ds`	338	`pop ds`
339	`pop dx`	339	`pop dx`
340	`pop cx`	340	`pop cx`
341	`pop bx`	341	`pop bx`
342	`pop ax`	342	`pop ax`
343	`}`	343	`}`
344	`outputnl("");`	344	`outputnl("");`
345		345
346	`/* if nothing entered, loop again */`	346	`/* if nothing entered, loop again */`
347	`if (cmdline[-1] == 0) continue;`	347	`if (cmdline[-1] == 0) continue;`
348		348
349	`/* replace \r by a zero terminator */`	349	`/* replace \r by a zero terminator */`
350	`cmdline[(unsigned char)(cmdline[-1])] = 0;`	350	`cmdline[(unsigned char)(cmdline[-1])] = 0;`
351		351
352	`/* move pointer forward to skip over any leading spaces */`	352	`/* move pointer forward to skip over any leading spaces */`
353	`while (*cmdline == ' ') cmdline++;`	353	`while (*cmdline == ' ') cmdline++;`
354		354
355	`/* update rmod's ptr to COMPSPEC so it is always up to date */`	355	`/* update rmod's ptr to COMPSPEC so it is always up to date */`
356	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`	356	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`
357		357
358	`/* try matching (and executing) an internal command */`	358	`/* try matching (and executing) an internal command */`
359	`{`	359	`{`
360	`int ecode = cmd_process(*rmod_envseg, cmdline, BUFFER);`	360	`int ecode = cmd_process(*rmod_envseg, cmdline, BUFFER);`
361	`if (ecode >= 0) *lastexitcode = ecode;`	361	`if (ecode >= 0) *lastexitcode = ecode;`
362	`if (ecode >= -1) { /* internal command executed */`	362	`if (ecode >= -1) { /* internal command executed */`
363	`outputnl("");`	363	`outputnl("");`
364	`continue;`	364	`continue;`
365	`}`	365	`}`
366	`}`	366	`}`
367		367
368	`/* if here, then this was not an internal command */`	368	`/* if here, then this was not an internal command */`
369	`run_as_external(cmdline);`	369	`run_as_external(cmdline);`
370		370
371	`/* execvp() replaces the current process by the new one`	371	`/* execvp() replaces the current process by the new one`
372	`if I am still alive then external command failed to execute */`	372	`if I am still alive then external command failed to execute */`
373	`outputnl("Bad command or file name");`	373	`outputnl("Bad command or file name");`
374		374
375	`}`	375	`}`
376		376
377	`return(0);`	377	`return(0);`
378	`}`	378	`}`
379		379

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c – Rev 377 → 397