WebSVN – SvarDOS – Diff – /svarcom/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) {
  struct config cfg;
  unsigned short rmod_seg;
  unsigned short far *rmod_envseg;
  unsigned short far *lastexitcode;
 
  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 buff[256];
      char *promptptr = buff;
      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);
      if (ecode >= 0) *lastexitcode = ecode;
      if (ecode >= -1) continue; /* internal command executed */
    }
 
    /* 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 369	Rev 370
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, const char fmt) {`	84	`static void buildprompt(char *s, unsigned short envseg) {`
-		85	`/* locate the prompt variable or use the default pattern */`
-		86	`const char far *fmt = env_lookup(envseg, "PROMPT");`
-		87	`while ((fmt != NULL) && (*fmt != 0)) {`
-		88	`fmt++;`
-		89	`if (fmt[-1] == '=') break;`
-		90	`}`
-		91	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
-		92	`/* build the prompt string based on pattern */`
85	`for (; *fmt != 0; fmt++) {`	93	`for (; *fmt != 0; fmt++) {`
86	`if (*fmt != '$') {`	94	`if (*fmt != '$') {`
87	`s = fmt;`	95	`s = fmt;`
88	`s++;`	96	`s++;`
89	`continue;`	97	`continue;`
90	`}`	98	`}`
91	`/* escape code ($P, etc) */`	99	`/* escape code ($P, etc) */`
92	`fmt++;`	100	`fmt++;`
93	`switch (*fmt) {`	101	`switch (*fmt) {`
94	`case 'Q': /* $Q = = (equal sign) */`	102	`case 'Q': /* $Q = = (equal sign) */`
95	`case 'q':`	103	`case 'q':`
96	`*s = '=';`	104	`*s = '=';`
97	`s++;`	105	`s++;`
98	`break;`	106	`break;`
99	`case '$': /* $$ = $ (dollar sign) */`	107	`case '$': /* $$ = $ (dollar sign) */`
100	`*s = '$';`	108	`*s = '$';`
101	`s++;`	109	`s++;`
102	`break;`	110	`break;`
103	`case 'T': /* $t = current time */`	111	`case 'T': /* $t = current time */`
104	`case 't':`	112	`case 't':`
105	`s += sprintf(s, "00:00"); /* TODO */`	113	`s += sprintf(s, "00:00"); /* TODO */`
106	`break;`	114	`break;`
107	`case 'D': /* $D = current date */`	115	`case 'D': /* $D = current date */`
108	`case 'd':`	116	`case 'd':`
109	`s += sprintf(s, "1985-07-29"); /* TODO */`	117	`s += sprintf(s, "1985-07-29"); /* TODO */`
110	`break;`	118	`break;`
111	`case 'P': /* $P = current drive and path */`	119	`case 'P': /* $P = current drive and path */`
112	`case 'p':`	120	`case 'p':`
113	`_asm {`	121	`_asm {`
114	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	122	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
115	`int 0x21`	123	`int 0x21`
116	`mov bx, s`	124	`mov bx, s`
117	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	125	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
118	`}`	126	`}`
119	`*s += 'A';`	127	`*s += 'A';`
120	`s++;`	128	`s++;`
121	`*s = ':';`	129	`*s = ':';`
122	`s++;`	130	`s++;`
123	`*s = '\\';`	131	`*s = '\\';`
124	`s++;`	132	`s++;`
125	`_asm {`	133	`_asm {`
126	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	134	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
127	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	135	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
128	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	136	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
129	`int 0x21`	137	`int 0x21`
130	`}`	138	`}`
131	`while (s != 0) s++; / move ptr forward to end of pathname */`	139	`while (s != 0) s++; / move ptr forward to end of pathname */`
132	`break;`	140	`break;`
133	`case 'V': /* $V = DOS version number */`	141	`case 'V': /* $V = DOS version number */`
134	`case 'v':`	142	`case 'v':`
135	`s += sprintf(s, "VER"); /* TODO */`	143	`s += sprintf(s, "VER"); /* TODO */`
136	`break;`	144	`break;`
137	`case 'N': /* $N = current drive */`	145	`case 'N': /* $N = current drive */`
138	`case 'n':`	146	`case 'n':`
139	`_asm {`	147	`_asm {`
140	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	148	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
141	`int 0x21`	149	`int 0x21`
142	`mov bx, s`	150	`mov bx, s`
143	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	151	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
144	`}`	152	`}`
145	`*s += 'A';`	153	`*s += 'A';`
146	`s++;`	154	`s++;`
147	`break;`	155	`break;`
148	`case 'G': /* $G = > (greater-than sign) */`	156	`case 'G': /* $G = > (greater-than sign) */`
149	`case 'g':`	157	`case 'g':`
150	`*s = '>';`	158	`*s = '>';`
151	`s++;`	159	`s++;`
152	`break;`	160	`break;`
153	`case 'L': /* $L = < (less-than sign) */`	161	`case 'L': /* $L = < (less-than sign) */`
154	`case 'l':`	162	`case 'l':`
155	`*s = '<';`	163	`*s = '<';`
156	`s++;`	164	`s++;`
157	`break;`	165	`break;`
158	`case 'B': /* $B = \| (pipe) */`	166	`case 'B': /* $B = \| (pipe) */`
159	`case 'b':`	167	`case 'b':`
160	`*s = '\|';`	168	`*s = '\|';`
161	`s++;`	169	`s++;`
162	`break;`	170	`break;`
163	`case 'H': /* $H = backspace (erases previous character) */`	171	`case 'H': /* $H = backspace (erases previous character) */`
164	`case 'h':`	172	`case 'h':`
165	`*s = '\b';`	173	`*s = '\b';`
166	`s++;`	174	`s++;`
167	`break;`	175	`break;`
168	`case 'E': /* $E = Escape code (ASCII 27) */`	176	`case 'E': /* $E = Escape code (ASCII 27) */`
169	`case 'e':`	177	`case 'e':`
170	`*s = 27;`	178	`*s = 27;`
171	`s++;`	179	`s++;`
172	`break;`	180	`break;`
173	`case '_': /* $_ = CR+LF */`	181	`case '_': /* $_ = CR+LF */`
174	`*s = '\r';`	182	`*s = '\r';`
175	`s++;`	183	`s++;`
176	`*s = '\n';`	184	`*s = '\n';`
177	`s++;`	185	`s++;`
178	`break;`	186	`break;`
179	`}`	187	`}`
180	`}`	188	`}`
181	`*s = '$';`	189	`*s = '$';`
182	`}`	190	`}`
183		191
184		192
185	`static void run_as_external(const char far *cmdline) {`	193	`static void run_as_external(const char far *cmdline) {`
186	`char buff[256];`	194	`char buff[256];`
187	`char const *argvlist[256];`	195	`char const *argvlist[256];`
188	`int i, n;`	196	`int i, n;`
189	`/* 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`
190	`every slash to make sure arguments are well separated */`	198	`every slash to make sure arguments are well separated */`
191	`n = 0;`	199	`n = 0;`
192	`i = 0;`	200	`i = 0;`
193	`for (;;) {`	201	`for (;;) {`
194	`if (cmdline[i] == '/') buff[n++] = ' ';`	202	`if (cmdline[i] == '/') buff[n++] = ' ';`
195	`buff[n++] = cmdline[i++];`	203	`buff[n++] = cmdline[i++];`
196	`if (buff[n] == 0) break;`	204	`if (buff[n] == 0) break;`
197	`}`	205	`}`
198		206
199	`cmd_explode(buff, cmdline, argvlist);`	207	`cmd_explode(buff, cmdline, argvlist);`
200		208
201	`/* 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]); */`
202		210
203	`/* 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`
204	`* the other program failed to be executed. */`	212	`* the other program failed to be executed. */`
205	`execvp(argvlist[0], argvlist);`	213	`execvp(argvlist[0], argvlist);`
206	`}`	214	`}`
207		215
208		216
209	`static void set_comspec_to_self(unsigned short envseg) {`	217	`static void set_comspec_to_self(unsigned short envseg) {`
210	`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 */`
211	`char far myenv = MK_FP(psp_envseg, 0);`	219	`char far myenv = MK_FP(psp_envseg, 0);`
212	`unsigned short varcount;`	220	`unsigned short varcount;`
213	`char buff[256] = "COMSPEC=";`	221	`char buff[256] = "COMSPEC=";`
214	`char *buffptr = buff + 8;`	222	`char *buffptr = buff + 8;`
215	`/* 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 */`
216	`while (*myenv != 0) {`	224	`while (*myenv != 0) {`
217	`/* consume a NULL-terminated string */`	225	`/* consume a NULL-terminated string */`
218	`while (*myenv != 0) myenv++;`	226	`while (*myenv != 0) myenv++;`
219	`/* move to next string */`	227	`/* move to next string */`
220	`myenv++;`	228	`myenv++;`
221	`}`	229	`}`
222	`/* get next word, if 1 then EXEPATH follows */`	230	`/* get next word, if 1 then EXEPATH follows */`
223	`myenv++;`	231	`myenv++;`
224	`varcount = *myenv;`	232	`varcount = *myenv;`
225	`myenv++;`	233	`myenv++;`
226	`varcount \|= (*myenv << 8);`	234	`varcount \|= (*myenv << 8);`
227	`myenv++;`	235	`myenv++;`
228	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	236	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
229	`while (*myenv != 0) {`	237	`while (*myenv != 0) {`
230	`buffptr = myenv;`	238	`buffptr = myenv;`
231	`buffptr++;`	239	`buffptr++;`
232	`myenv++;`	240	`myenv++;`
233	`}`	241	`}`
234	`*buffptr = 0;`	242	`*buffptr = 0;`
235	`/* printf("EXEPATH: '%s'\r\n", buff); */`	243	`/* printf("EXEPATH: '%s'\r\n", buff); */`
236	`env_setvar(envseg, buff);`	244	`env_setvar(envseg, buff);`
237	`}`	245	`}`
238		246
239		247
240	`int main(int argc, char **argv) {`	248	`int main(int argc, char **argv) {`
241	`struct config cfg;`	249	`struct config cfg;`
242	`unsigned short rmod_seg;`	250	`unsigned short rmod_seg;`
243	`unsigned short far *rmod_envseg;`	251	`unsigned short far *rmod_envseg;`
244	`unsigned short far *lastexitcode;`	252	`unsigned short far *lastexitcode;`
245		253
246	`parse_argv(&cfg, argc, argv);`	254	`parse_argv(&cfg, argc, argv);`
247		255
248	`rmod_seg = rmod_find();`	256	`rmod_seg = rmod_find();`
249	`if (rmod_seg == 0xffff) {`	257	`if (rmod_seg == 0xffff) {`
250	`rmod_seg = rmod_install(cfg.envsiz);`	258	`rmod_seg = rmod_install(cfg.envsiz);`
251	`if (rmod_seg == 0xffff) {`	259	`if (rmod_seg == 0xffff) {`
252	`outputnl("ERROR: rmod_install() failed");`	260	`outputnl("ERROR: rmod_install() failed");`
253	`return(1);`	261	`return(1);`
254	`}`	262	`}`
255	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`	263	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`
256	`} else {`	264	`} else {`
257	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`	265	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`
258	`}`	266	`}`
259		267
260	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`	268	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`
261	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`	269	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`
262		270
263	`/* make COMPSEC point to myself */`	271	`/* make COMPSEC point to myself */`
264	`set_comspec_to_self(*rmod_envseg);`	272	`set_comspec_to_self(*rmod_envseg);`
265		273
266	`/* {`	274	`/* {`
267	`unsigned short envsiz;`	275	`unsigned short envsiz;`
268	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`	276	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`
269	`envsiz = *sizptr;`	277	`envsiz = *sizptr;`
270	`envsiz *= 16;`	278	`envsiz *= 16;`
271	`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);`	279	`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);`
272	`}*/`	280	`}*/`
273		281
274	`for (;;) {`	282	`for (;;) {`
275	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`	283	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`
276		284
277	`/* revert input history terminator to \r */`	285	`/* revert input history terminator to \r */`
278	`if (cmdline[-1] != 0) {`	286	`if (cmdline[-1] != 0) {`
279	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`	287	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`
280	`}`	288	`}`
281		289
282	`{`	290	`{`
283	`/* print shell prompt */`	291	`/* print shell prompt */`
284	`char buff[256];`	292	`char buff[256];`
285	`char *promptptr = buff;`	293	`char *promptptr = buff;`
286	`buildprompt(promptptr, "$p$g"); /* TODO: prompt should be configurable via environment */`	294	`buildprompt(promptptr, *rmod_envseg);`
287	`_asm {`	295	`_asm {`
288	`push ax`	296	`push ax`
289	`push dx`	297	`push dx`
290	`mov ah, 0x09`	298	`mov ah, 0x09`
291	`mov dx, promptptr`	299	`mov dx, promptptr`
292	`int 0x21`	300	`int 0x21`
293	`pop dx`	301	`pop dx`
294	`pop ax`	302	`pop ax`
295	`}`	303	`}`
296	`}`	304	`}`
297		305
298	`/* wait for user input */`	306	`/* wait for user input */`
299	`_asm {`	307	`_asm {`
300	`push ax`	308	`push ax`
301	`push bx`	309	`push bx`
302	`push cx`	310	`push cx`
303	`push dx`	311	`push dx`
304	`push ds`	312	`push ds`
305		313
306	`/* 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) */`
307	`mov ax, 0x4800`	315	`mov ax, 0x4800`
308	`int 0x2f`	316	`int 0x2f`
309	`mov bl, al /* save doskey status in BL */`	317	`mov bl, al /* save doskey status in BL */`
310		318
311	`/* set up buffered input */`	319	`/* set up buffered input */`
312	`mov ax, rmod_seg`	320	`mov ax, rmod_seg`
313	`push ax`	321	`push ax`
314	`pop ds`	322	`pop ds`
315	`mov dx, RMOD_OFFSET_INPBUFF`	323	`mov dx, RMOD_OFFSET_INPBUFF`
316		324
317	`/* execute either DOS input or DOSKEY */`	325	`/* execute either DOS input or DOSKEY */`
318	`test bl, bl /* zf set if no DOSKEY present */`	326	`test bl, bl /* zf set if no DOSKEY present */`
319	`jnz DOSKEY`	327	`jnz DOSKEY`
320		328
321	`mov ah, 0x0a`	329	`mov ah, 0x0a`
322	`int 0x21`	330	`int 0x21`
323	`jmp short DONE`	331	`jmp short DONE`
324		332
325	`DOSKEY:`	333	`DOSKEY:`
326	`mov ax, 0x4810`	334	`mov ax, 0x4810`
327	`int 0x2f`	335	`int 0x2f`
328		336
329	`DONE:`	337	`DONE:`
330	`pop ds`	338	`pop ds`
331	`pop dx`	339	`pop dx`
332	`pop cx`	340	`pop cx`
333	`pop bx`	341	`pop bx`
334	`pop ax`	342	`pop ax`
335	`}`	343	`}`
336	`outputnl("");`	344	`outputnl("");`
337		345
338	`/* if nothing entered, loop again */`	346	`/* if nothing entered, loop again */`
339	`if (cmdline[-1] == 0) continue;`	347	`if (cmdline[-1] == 0) continue;`
340		348
341	`/* replace \r by a zero terminator */`	349	`/* replace \r by a zero terminator */`
342	`cmdline[(unsigned char)(cmdline[-1])] = 0;`	350	`cmdline[(unsigned char)(cmdline[-1])] = 0;`
343		351
344	`/* move pointer forward to skip over any leading spaces */`	352	`/* move pointer forward to skip over any leading spaces */`
345	`while (*cmdline == ' ') cmdline++;`	353	`while (*cmdline == ' ') cmdline++;`
346		354
347	`/* 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 */`
348	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`	356	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`
349		357
350	`/* try matching (and executing) an internal command */`	358	`/* try matching (and executing) an internal command */`
351	`{`	359	`{`
352	`int ecode = cmd_process(*rmod_envseg, cmdline);`	360	`int ecode = cmd_process(*rmod_envseg, cmdline);`
353	`if (ecode >= 0) *lastexitcode = ecode;`	361	`if (ecode >= 0) *lastexitcode = ecode;`
354	`if (ecode >= -1) continue; /* internal command executed */`	362	`if (ecode >= -1) continue; /* internal command executed */`
355	`}`	363	`}`
356		364
357	`/* if here, then this was not an internal command */`	365	`/* if here, then this was not an internal command */`
358	`run_as_external(cmdline);`	366	`run_as_external(cmdline);`
359		367
360	`/* execvp() replaces the current process by the new one`	368	`/* execvp() replaces the current process by the new one`
361	`if I am still alive then external command failed to execute */`	369	`if I am still alive then external command failed to execute */`
362	`outputnl("Bad command or file name");`	370	`outputnl("Bad command or file name");`
363		371
364	`}`	372	`}`
365		373
366	`return(0);`	374	`return(0);`
367	`}`	375	`}`
368		376

Subversion Repositories SvarDOS

(root)/svarcom/command.c @ 371 – Rev 369 → 370