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.
 *
 
 
 
 
 
 * 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 "redir.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);
    unsigned char far *echostatus = MK_FP(rmod_seg, RMOD_OFFSET_ECHOFLAG);
 
    if (*echostatus != 0) outputnl(""); /* terminate the previous command with a CR/LF */
 
 
 
 
    SKIP_NEWLINE:
 
    /* print shell prompt (only if ECHO is enabled) */
    if (*echostatus != 0) {
      char *promptptr = BUFFER;
      buildprompt(promptptr, *rmod_envseg);
      _asm {
        push ax
        push dx
        mov ah, 0x09
        mov dx, promptptr
        int 0x21
        pop dx
        pop ax
      }
    }
 
    /* revert input history terminator to \r */
    if (cmdline[-1] != 0) {
      cmdline[(unsigned short)(cmdline[-1])] = '\r';
    }
 
    /* 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:
      /* terminate command with a CR/LF */
      mov ah, 0x02 /* display character in dl */
      mov dl, 0x0d
      int 0x21
      mov dl, 0x0a
      int 0x21
 
      pop ds
      pop dx
      pop cx
      pop bx
      pop ax
    }
 
 
    /* if nothing entered, loop again (but without appending an extra CR/LF) */
    if (cmdline[-1] == 0) goto SKIP_NEWLINE;
 
    /* 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);
 
    /* handle redirections (if any) */
    if (redir_parsecmd(cmdline, BUFFER) != 0) {
      outputnl("");
      continue;
    }
 
    /* try matching (and executing) an internal command */
    {
      int ecode = cmd_process(rmod_seg, *rmod_envseg, cmdline, BUFFER);
      if (ecode >= 0) *lastexitcode = ecode;
      if (ecode >= -1) { /* internal command executed */
        redir_revert(); /* revert stdout (in case it was redirected) */
 
        continue;
      }
    }
 
    /* if here, then this was not an internal command */
    run_as_external(cmdline);
 
    /* revert stdout (in case it was redirected) */
    redir_revert();
 
    /* 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 402	Rev 405
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	`*`	-
19	`*`	-
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`	-
22	`*`	-
23	`* PSP structure`	18	`* PSP structure`
24	`* http://www.piclist.com/techref/dos/psps.htm`	19	`* http://www.piclist.com/techref/dos/psps.htm`
25	`*`	20	`*`
26	`*`	21	`*`
27	`*`	22	`*`
28	`* === MCB ===`	23	`* === MCB ===`
29	`*`	24	`*`
30	`* each time that DOS allocates memory, it prefixes the allocated memory with`	25	`* 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`	26	`* a 16-bytes structure called a "Memory Control Block" (MCB). This control`
32	`* block has the following structure:`	27	`* block has the following structure:`
33	`*`	28	`*`
34	`* Offset Size Description`	29	`* Offset Size Description`
35	`* 00h byte 'M' = non-last member of the MCB chain`	30	`* 00h byte 'M' = non-last member of the MCB chain`
36	`* 'Z' = indicates last entry in MCB chain`	31	`* 'Z' = indicates last entry in MCB chain`
37	`* other values cause "Memory Allocation Failure" on exit`	32	`* other values cause "Memory Allocation Failure" on exit`
38	`* 01h word PSP segment address of the owner (Process Id)`	33	`* 01h word PSP segment address of the owner (Process Id)`
39	`* possible values:`	34	`* possible values:`
40	`* 0 = free`	35	`* 0 = free`
41	`* 8 = Allocated by DOS before first user pgm loaded`	36	`* 8 = Allocated by DOS before first user pgm loaded`
42	`* other = Process Id/PSP segment address of owner`	37	`* other = Process Id/PSP segment address of owner`
43	`* 03h word number of paragraphs related to this MCB (excluding MCB)`	38	`* 03h word number of paragraphs related to this MCB (excluding MCB)`
44	`* 05h 11 bytes reserved`	39	`* 05h 11 bytes reserved`
45	`* 10h ... start of actual allocated memory block`	40	`* 10h ... start of actual allocated memory block`
46	`*/`	41	`*/`
47		42
48	`#include <i86.h>`	43	`#include <i86.h>`
49	`#include <dos.h>`	44	`#include <dos.h>`
50	`#include <stdio.h>`	45	`#include <stdio.h>`
51	`#include <stdlib.h>`	46	`#include <stdlib.h>`
52	`#include <string.h>`	47	`#include <string.h>`
53		48
54	`#include <process.h>`	49	`#include <process.h>`
55		50
56	`#include "cmd.h"`	51	`#include "cmd.h"`
57	`#include "env.h"`	52	`#include "env.h"`
58	`#include "helpers.h"`	53	`#include "helpers.h"`
59	`#include "redir.h"`	54	`#include "redir.h"`
60	`#include "rmodinit.h"`	55	`#include "rmodinit.h"`
61		56
62	`struct config {`	57	`struct config {`
63	`int locate;`	58	`int locate;`
64	`int install;`	59	`int install;`
65	`int envsiz;`	60	`int envsiz;`
66	`} cfg;`	61	`} cfg;`
67		62
68		63
69	`static void parse_argv(struct config cfg, int argc, char *argv) {`	64	`static void parse_argv(struct config cfg, int argc, char *argv) {`
70	`int i;`	65	`int i;`
71	`memset(cfg, 0, sizeof(*cfg));`	66	`memset(cfg, 0, sizeof(*cfg));`
72		67
73	`for (i = 1; i < argc; i++) {`	68	`for (i = 1; i < argc; i++) {`
74	`if (strcmp(argv[i], "/locate") == 0) {`	69	`if (strcmp(argv[i], "/locate") == 0) {`
75	`cfg->locate = 1;`	70	`cfg->locate = 1;`
76	`}`	71	`}`
77	`if (strstartswith(argv[i], "/e:") == 0) {`	72	`if (strstartswith(argv[i], "/e:") == 0) {`
78	`cfg->envsiz = atoi(argv[i]+3);`	73	`cfg->envsiz = atoi(argv[i]+3);`
79	`if (cfg->envsiz < 64) cfg->envsiz = 0;`	74	`if (cfg->envsiz < 64) cfg->envsiz = 0;`
80	`}`	75	`}`
81	`}`	76	`}`
82	`}`	77	`}`
83		78
84		79
85	`static void buildprompt(char *s, unsigned short envseg) {`	80	`static void buildprompt(char *s, unsigned short envseg) {`
86	`/* locate the prompt variable or use the default pattern */`	81	`/* locate the prompt variable or use the default pattern */`
87	`const char far *fmt = env_lookup(envseg, "PROMPT");`	82	`const char far *fmt = env_lookup(envseg, "PROMPT");`
88	`while ((fmt != NULL) && (*fmt != 0)) {`	83	`while ((fmt != NULL) && (*fmt != 0)) {`
89	`fmt++;`	84	`fmt++;`
90	`if (fmt[-1] == '=') break;`	85	`if (fmt[-1] == '=') break;`
91	`}`	86	`}`
92	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`	87	`if ((fmt == NULL) \|\| (fmt == 0)) fmt = "$p$g"; / fallback to default if empty */`
93	`/* build the prompt string based on pattern */`	88	`/* build the prompt string based on pattern */`
94	`for (; *fmt != 0; fmt++) {`	89	`for (; *fmt != 0; fmt++) {`
95	`if (*fmt != '$') {`	90	`if (*fmt != '$') {`
96	`s = fmt;`	91	`s = fmt;`
97	`s++;`	92	`s++;`
98	`continue;`	93	`continue;`
99	`}`	94	`}`
100	`/* escape code ($P, etc) */`	95	`/* escape code ($P, etc) */`
101	`fmt++;`	96	`fmt++;`
102	`switch (*fmt) {`	97	`switch (*fmt) {`
103	`case 'Q': /* $Q = = (equal sign) */`	98	`case 'Q': /* $Q = = (equal sign) */`
104	`case 'q':`	99	`case 'q':`
105	`*s = '=';`	100	`*s = '=';`
106	`s++;`	101	`s++;`
107	`break;`	102	`break;`
108	`case '$': /* $$ = $ (dollar sign) */`	103	`case '$': /* $$ = $ (dollar sign) */`
109	`*s = '$';`	104	`*s = '$';`
110	`s++;`	105	`s++;`
111	`break;`	106	`break;`
112	`case 'T': /* $t = current time */`	107	`case 'T': /* $t = current time */`
113	`case 't':`	108	`case 't':`
114	`s += sprintf(s, "00:00"); /* TODO */`	109	`s += sprintf(s, "00:00"); /* TODO */`
115	`break;`	110	`break;`
116	`case 'D': /* $D = current date */`	111	`case 'D': /* $D = current date */`
117	`case 'd':`	112	`case 'd':`
118	`s += sprintf(s, "1985-07-29"); /* TODO */`	113	`s += sprintf(s, "1985-07-29"); /* TODO */`
119	`break;`	114	`break;`
120	`case 'P': /* $P = current drive and path */`	115	`case 'P': /* $P = current drive and path */`
121	`case 'p':`	116	`case 'p':`
122	`_asm {`	117	`_asm {`
123	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	118	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
124	`int 0x21`	119	`int 0x21`
125	`mov bx, s`	120	`mov bx, s`
126	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	121	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
127	`}`	122	`}`
128	`*s += 'A';`	123	`*s += 'A';`
129	`s++;`	124	`s++;`
130	`*s = ':';`	125	`*s = ':';`
131	`s++;`	126	`s++;`
132	`*s = '\\';`	127	`*s = '\\';`
133	`s++;`	128	`s++;`
134	`_asm {`	129	`_asm {`
135	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`	130	`mov ah, 0x47 /* DOS 2+ - CWD - GET CURRENT DIRECTORY */`
136	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`	131	`xor dl,dl /* DL = drive number (00h = default, 01h = A:, etc) */`
137	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`	132	`mov si, s /* DS:SI -> 64-byte buffer for ASCIZ pathname */`
138	`int 0x21`	133	`int 0x21`
139	`}`	134	`}`
140	`while (s != 0) s++; / move ptr forward to end of pathname */`	135	`while (s != 0) s++; / move ptr forward to end of pathname */`
141	`break;`	136	`break;`
142	`case 'V': /* $V = DOS version number */`	137	`case 'V': /* $V = DOS version number */`
143	`case 'v':`	138	`case 'v':`
144	`s += sprintf(s, "VER"); /* TODO */`	139	`s += sprintf(s, "VER"); /* TODO */`
145	`break;`	140	`break;`
146	`case 'N': /* $N = current drive */`	141	`case 'N': /* $N = current drive */`
147	`case 'n':`	142	`case 'n':`
148	`_asm {`	143	`_asm {`
149	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`	144	`mov ah, 0x19 /* DOS 1+ - GET CURRENT DRIVE */`
150	`int 0x21`	145	`int 0x21`
151	`mov bx, s`	146	`mov bx, s`
152	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`	147	`mov [bx], al /* AL = drive (00 = A:, 01 = B:, etc */`
153	`}`	148	`}`
154	`*s += 'A';`	149	`*s += 'A';`
155	`s++;`	150	`s++;`
156	`break;`	151	`break;`
157	`case 'G': /* $G = > (greater-than sign) */`	152	`case 'G': /* $G = > (greater-than sign) */`
158	`case 'g':`	153	`case 'g':`
159	`*s = '>';`	154	`*s = '>';`
160	`s++;`	155	`s++;`
161	`break;`	156	`break;`
162	`case 'L': /* $L = < (less-than sign) */`	157	`case 'L': /* $L = < (less-than sign) */`
163	`case 'l':`	158	`case 'l':`
164	`*s = '<';`	159	`*s = '<';`
165	`s++;`	160	`s++;`
166	`break;`	161	`break;`
167	`case 'B': /* $B = \| (pipe) */`	162	`case 'B': /* $B = \| (pipe) */`
168	`case 'b':`	163	`case 'b':`
169	`*s = '\|';`	164	`*s = '\|';`
170	`s++;`	165	`s++;`
171	`break;`	166	`break;`
172	`case 'H': /* $H = backspace (erases previous character) */`	167	`case 'H': /* $H = backspace (erases previous character) */`
173	`case 'h':`	168	`case 'h':`
174	`*s = '\b';`	169	`*s = '\b';`
175	`s++;`	170	`s++;`
176	`break;`	171	`break;`
177	`case 'E': /* $E = Escape code (ASCII 27) */`	172	`case 'E': /* $E = Escape code (ASCII 27) */`
178	`case 'e':`	173	`case 'e':`
179	`*s = 27;`	174	`*s = 27;`
180	`s++;`	175	`s++;`
181	`break;`	176	`break;`
182	`case '_': /* $_ = CR+LF */`	177	`case '_': /* $_ = CR+LF */`
183	`*s = '\r';`	178	`*s = '\r';`
184	`s++;`	179	`s++;`
185	`*s = '\n';`	180	`*s = '\n';`
186	`s++;`	181	`s++;`
187	`break;`	182	`break;`
188	`}`	183	`}`
189	`}`	184	`}`
190	`*s = '$';`	185	`*s = '$';`
191	`}`	186	`}`
192		187
193		188
194	`static void run_as_external(const char far *cmdline) {`	189	`static void run_as_external(const char far *cmdline) {`
195	`char buff[256];`	190	`char buff[256];`
196	`char const *argvlist[256];`	191	`char const *argvlist[256];`
197	`int i, n;`	192	`int i, n;`
198	`/* copy buffer to a near var (incl. trailing CR), insert a space before`	193	`/* copy buffer to a near var (incl. trailing CR), insert a space before`
199	`every slash to make sure arguments are well separated */`	194	`every slash to make sure arguments are well separated */`
200	`n = 0;`	195	`n = 0;`
201	`i = 0;`	196	`i = 0;`
202	`for (;;) {`	197	`for (;;) {`
203	`if (cmdline[i] == '/') buff[n++] = ' ';`	198	`if (cmdline[i] == '/') buff[n++] = ' ';`
204	`buff[n++] = cmdline[i++];`	199	`buff[n++] = cmdline[i++];`
205	`if (buff[n] == 0) break;`	200	`if (buff[n] == 0) break;`
206	`}`	201	`}`
207		202
208	`cmd_explode(buff, cmdline, argvlist);`	203	`cmd_explode(buff, cmdline, argvlist);`
209		204
210	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`	205	`/* for (i = 0; argvlist[i] != NULL; i++) printf("arg #%d = '%s'\r\n", i, argvlist[i]); */`
211		206
212	`/* must be an external command then. this call should never return, unless`	207	`/* must be an external command then. this call should never return, unless`
213	`* the other program failed to be executed. */`	208	`* the other program failed to be executed. */`
214	`execvp(argvlist[0], argvlist);`	209	`execvp(argvlist[0], argvlist);`
215	`}`	210	`}`
216		211
217		212
218	`static void set_comspec_to_self(unsigned short envseg) {`	213	`static void set_comspec_to_self(unsigned short envseg) {`
219	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`	214	`unsigned short psp_envseg = (void )(0x2c); /* pointer to my env segment field in the PSP */`
220	`char far myenv = MK_FP(psp_envseg, 0);`	215	`char far myenv = MK_FP(psp_envseg, 0);`
221	`unsigned short varcount;`	216	`unsigned short varcount;`
222	`char buff[256] = "COMSPEC=";`	217	`char buff[256] = "COMSPEC=";`
223	`char *buffptr = buff + 8;`	218	`char *buffptr = buff + 8;`
224	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`	219	`/* who am i? look into my own environment, at the end of it should be my EXEPATH string */`
225	`while (*myenv != 0) {`	220	`while (*myenv != 0) {`
226	`/* consume a NULL-terminated string */`	221	`/* consume a NULL-terminated string */`
227	`while (*myenv != 0) myenv++;`	222	`while (*myenv != 0) myenv++;`
228	`/* move to next string */`	223	`/* move to next string */`
229	`myenv++;`	224	`myenv++;`
230	`}`	225	`}`
231	`/* get next word, if 1 then EXEPATH follows */`	226	`/* get next word, if 1 then EXEPATH follows */`
232	`myenv++;`	227	`myenv++;`
233	`varcount = *myenv;`	228	`varcount = *myenv;`
234	`myenv++;`	229	`myenv++;`
235	`varcount \|= (*myenv << 8);`	230	`varcount \|= (*myenv << 8);`
236	`myenv++;`	231	`myenv++;`
237	`if (varcount != 1) return; /* NO EXEPATH FOUND */`	232	`if (varcount != 1) return; /* NO EXEPATH FOUND */`
238	`while (*myenv != 0) {`	233	`while (*myenv != 0) {`
239	`buffptr = myenv;`	234	`buffptr = myenv;`
240	`buffptr++;`	235	`buffptr++;`
241	`myenv++;`	236	`myenv++;`
242	`}`	237	`}`
243	`*buffptr = 0;`	238	`*buffptr = 0;`
244	`/* printf("EXEPATH: '%s'\r\n", buff); */`	239	`/* printf("EXEPATH: '%s'\r\n", buff); */`
245	`env_setvar(envseg, buff);`	240	`env_setvar(envseg, buff);`
246	`}`	241	`}`
247		242
248		243
249	`int main(int argc, char **argv) {`	244	`int main(int argc, char **argv) {`
250	`static struct config cfg;`	245	`static struct config cfg;`
251	`static unsigned short rmod_seg;`	246	`static unsigned short rmod_seg;`
252	`static unsigned short far *rmod_envseg;`	247	`static unsigned short far *rmod_envseg;`
253	`static unsigned short far *lastexitcode;`	248	`static unsigned short far *lastexitcode;`
254	`static unsigned char BUFFER[4096];`	249	`static unsigned char BUFFER[4096];`
255		250
256	`parse_argv(&cfg, argc, argv);`	251	`parse_argv(&cfg, argc, argv);`
257		252
258	`rmod_seg = rmod_find();`	253	`rmod_seg = rmod_find();`
259	`if (rmod_seg == 0xffff) {`	254	`if (rmod_seg == 0xffff) {`
260	`rmod_seg = rmod_install(cfg.envsiz);`	255	`rmod_seg = rmod_install(cfg.envsiz);`
261	`if (rmod_seg == 0xffff) {`	256	`if (rmod_seg == 0xffff) {`
262	`outputnl("ERROR: rmod_install() failed");`	257	`outputnl("ERROR: rmod_install() failed");`
263	`return(1);`	258	`return(1);`
264	`}`	259	`}`
265	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`	260	`/* printf("rmod installed at seg 0x%04X\r\n", rmod_seg); */`
266	`} else {`	261	`} else {`
267	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`	262	`/* printf("rmod found at seg 0x%04x\r\n", rmod_seg); */`
268	`}`	263	`}`
269		264
270	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`	265	`rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG);`
271	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`	266	`lastexitcode = MK_FP(rmod_seg, RMOD_OFFSET_LEXITCODE);`
272		267
273	`/* make COMPSEC point to myself */`	268	`/* make COMPSEC point to myself */`
274	`set_comspec_to_self(*rmod_envseg);`	269	`set_comspec_to_self(*rmod_envseg);`
275		270
276	`/* {`	271	`/* {`
277	`unsigned short envsiz;`	272	`unsigned short envsiz;`
278	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`	273	`unsigned short far sizptr = MK_FP(rmod_envseg - 1, 3);`
279	`envsiz = *sizptr;`	274	`envsiz = *sizptr;`
280	`envsiz *= 16;`	275	`envsiz *= 16;`
281	`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);`	276	`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);`
282	`}*/`	277	`}*/`
283		278
284	`for (;;) {`	279	`for (;;) {`
285	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`	280	`char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2);`
-		281	`unsigned char far *echostatus = MK_FP(rmod_seg, RMOD_OFFSET_ECHOFLAG);`
286		282
287	`/* revert input history terminator to \r */`	283	`if (echostatus != 0) outputnl(""); / terminate the previous command with a CR/LF */`
288	`if (cmdline[-1] != 0) {`	-
289	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`	-
290	`}`	-
291		284
292	`{`	285	`SKIP_NEWLINE:`
-		286
293	`/* print shell prompt */`	287	`/* print shell prompt (only if ECHO is enabled) */`
-		288	`if (*echostatus != 0) {`
294	`char *promptptr = BUFFER;`	289	`char *promptptr = BUFFER;`
295	`buildprompt(promptptr, *rmod_envseg);`	290	`buildprompt(promptptr, *rmod_envseg);`
296	`_asm {`	291	`_asm {`
297	`push ax`	292	`push ax`
298	`push dx`	293	`push dx`
299	`mov ah, 0x09`	294	`mov ah, 0x09`
300	`mov dx, promptptr`	295	`mov dx, promptptr`
301	`int 0x21`	296	`int 0x21`
302	`pop dx`	297	`pop dx`
303	`pop ax`	298	`pop ax`
304	`}`	299	`}`
305	`}`	300	`}`
306		301
-		302	`/* revert input history terminator to \r */`
-		303	`if (cmdline[-1] != 0) {`
-		304	`cmdline[(unsigned short)(cmdline[-1])] = '\r';`
-		305	`}`
-		306
307	`/* wait for user input */`	307	`/* wait for user input */`
308	`_asm {`	308	`_asm {`
309	`push ax`	309	`push ax`
310	`push bx`	310	`push bx`
311	`push cx`	311	`push cx`
312	`push dx`	312	`push dx`
313	`push ds`	313	`push ds`
314		314
315	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`	315	`/* is DOSKEY support present? (INT 2Fh, AX=4800h, returns non-zero in AL if present) */`
316	`mov ax, 0x4800`	316	`mov ax, 0x4800`
317	`int 0x2f`	317	`int 0x2f`
318	`mov bl, al /* save doskey status in BL */`	318	`mov bl, al /* save doskey status in BL */`
319		319
320	`/* set up buffered input */`	320	`/* set up buffered input */`
321	`mov ax, rmod_seg`	321	`mov ax, rmod_seg`
322	`push ax`	322	`push ax`
323	`pop ds`	323	`pop ds`
324	`mov dx, RMOD_OFFSET_INPBUFF`	324	`mov dx, RMOD_OFFSET_INPBUFF`
325		325
326	`/* execute either DOS input or DOSKEY */`	326	`/* execute either DOS input or DOSKEY */`
327	`test bl, bl /* zf set if no DOSKEY present */`	327	`test bl, bl /* zf set if no DOSKEY present */`
328	`jnz DOSKEY`	328	`jnz DOSKEY`
329		329
330	`mov ah, 0x0a`	330	`mov ah, 0x0a`
331	`int 0x21`	331	`int 0x21`
332	`jmp short DONE`	332	`jmp short DONE`
333		333
334	`DOSKEY:`	334	`DOSKEY:`
335	`mov ax, 0x4810`	335	`mov ax, 0x4810`
336	`int 0x2f`	336	`int 0x2f`
337		337
338	`DONE:`	338	`DONE:`
-		339	`/* terminate command with a CR/LF */`
-		340	`mov ah, 0x02 /* display character in dl */`
-		341	`mov dl, 0x0d`
-		342	`int 0x21`
-		343	`mov dl, 0x0a`
-		344	`int 0x21`
-		345
339	`pop ds`	346	`pop ds`
340	`pop dx`	347	`pop dx`
341	`pop cx`	348	`pop cx`
342	`pop bx`	349	`pop bx`
343	`pop ax`	350	`pop ax`
344	`}`	351	`}`
345	`outputnl("");`	-
346		352
347	`/* if nothing entered, loop again */`	353	`/* if nothing entered, loop again (but without appending an extra CR/LF) */`
348	`if (cmdline[-1] == 0) continue;`	354	`if (cmdline[-1] == 0) goto SKIP_NEWLINE;`
349		355
350	`/* replace \r by a zero terminator */`	356	`/* replace \r by a zero terminator */`
351	`cmdline[(unsigned char)(cmdline[-1])] = 0;`	357	`cmdline[(unsigned char)(cmdline[-1])] = 0;`
352		358
353	`/* move pointer forward to skip over any leading spaces */`	359	`/* move pointer forward to skip over any leading spaces */`
354	`while (*cmdline == ' ') cmdline++;`	360	`while (*cmdline == ' ') cmdline++;`
355		361
356	`/* update rmod's ptr to COMPSPEC so it is always up to date */`	362	`/* update rmod's ptr to COMPSPEC so it is always up to date */`
357	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`	363	`rmod_updatecomspecptr(rmod_seg, *rmod_envseg);`
358		364
359	`/* handle redirections (if any) */`	365	`/* handle redirections (if any) */`
360	`if (redir_parsecmd(cmdline, BUFFER) != 0) {`	366	`if (redir_parsecmd(cmdline, BUFFER) != 0) {`
361	`outputnl("");`	367	`outputnl("");`
362	`continue;`	368	`continue;`
363	`}`	369	`}`
364		370
365	`/* try matching (and executing) an internal command */`	371	`/* try matching (and executing) an internal command */`
366	`{`	372	`{`
367	`int ecode = cmd_process(*rmod_envseg, cmdline, BUFFER);`	373	`int ecode = cmd_process(rmod_seg, *rmod_envseg, cmdline, BUFFER);`
368	`if (ecode >= 0) *lastexitcode = ecode;`	374	`if (ecode >= 0) *lastexitcode = ecode;`
369	`if (ecode >= -1) { /* internal command executed */`	375	`if (ecode >= -1) { /* internal command executed */`
370	`redir_revert(); /* revert stdout (in case it was redirected) */`	376	`redir_revert(); /* revert stdout (in case it was redirected) */`
371	`outputnl("");`	-
372	`continue;`	377	`continue;`
373	`}`	378	`}`
374	`}`	379	`}`
375		380
376	`/* if here, then this was not an internal command */`	381	`/* if here, then this was not an internal command */`
377	`run_as_external(cmdline);`	382	`run_as_external(cmdline);`
378		383
379	`/* revert stdout (in case it was redirected) */`	384	`/* revert stdout (in case it was redirected) */`
380	`redir_revert();`	385	`redir_revert();`
381		386
382	`/* execvp() replaces the current process by the new one`	387	`/* execvp() replaces the current process by the new one`
383	`if I am still alive then external command failed to execute */`	388	`if I am still alive then external command failed to execute */`
384	`outputnl("Bad command or file name");`	389	`outputnl("Bad command or file name");`
385		390
386	`}`	391	`}`
387		392
388	`return(0);`	393	`return(0);`
389	`}`	394	`}`
390		395

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c @ 470 – Rev 402 → 405