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Annotation of coherent/d/usr/bin/elvis/sysdos.c, revision 1.1

1.1     ! root        1: /* sysdos.c  -- DOS version of system.c */
        !             2: 
        !             3: /* Author:
        !             4:  *     Guntram Blohm
        !             5:  *     Buchenstrasse 19
        !             6:  *     7904 Erbach, West Germany
        !             7:  *     Tel. ++49-7305-6997
        !             8:  *     sorry - no regular network connection
        !             9:  */
        !            10: 
        !            11: 
        !            12: /* This file is derived from Steve Kirkendall's system.c.
        !            13:  *
        !            14:  * Entry points are:
        !            15:  *     system(cmd)     - run a single shell command
        !            16:  *     wildcard(names) - expand wildcard characters in filanames
        !            17:  *
        !            18:  * This file is for use with DOS and TOS. For OS/2, slight modifications
        !            19:  * might be sufficient. For UNIX, use system.c. For Amiga, completely
        !            20:  * rewrite this stuff.
        !            21:  *
        !            22:  * Another system function, filter, is the same on DOS and UNIX and thus
        !            23:  * can be found in the original system.c.
        !            24:  */
        !            25: 
        !            26: #include "config.h"
        !            27: #include "vi.h"
        !            28: extern char **environ;
        !            29: 
        !            30: 
        !            31: #if MSDOS
        !            32: #include <process.h>
        !            33: extern unsigned char _osmajor;
        !            34: #endif
        !            35: #if TOS
        !            36: #include <osbind.h>
        !            37: #endif
        !            38: 
        !            39: #if MSDOS || TOS
        !            40: #include <string.h>
        !            41: 
        !            42: /*
        !            43:  * Calling command is a bit nasty because of the undocumented yet sometimes
        !            44:  * used feature to change the option char to something else than /.
        !            45:  * Versions 2.x and 3.x support this, 4.x doesn't.
        !            46:  *
        !            47:  * For Atari, some shells define a shortcut entry which is faster than
        !            48:  * shell -c. Also, Mark Williams uses a special ARGV environment variable
        !            49:  * to pass more than 128 chars to a called command.
        !            50:  * We try to support all of these features here.
        !            51:  */
        !            52: 
        !            53: int system(cmd)
        !            54:        const char      *cmd;
        !            55: {
        !            56: #if MSDOS
        !            57:        char *cmdswitch="/c";
        !            58:        if (_osmajor<4)
        !            59:                cmdswitch[0]=switchar();
        !            60:        return spawnle(P_WAIT, o_shell, o_shell, cmdswitch, cmd, (char *)0, environ);
        !            61: #else
        !            62:        long    ssp;
        !            63:        int     (*shell)();
        !            64:        char    line[130];
        !            65:        char    env[4096], *ep=env;
        !            66:        int     i;
        !            67: 
        !            68: /* does our shell have a shortcut, that we can use? */
        !            69: 
        !            70:        ssp = Super(0L);
        !            71:        shell = *((int (**)())0x4F6);
        !            72:        Super(ssp);
        !            73:        if (shell)
        !            74:                return (*shell)(cmd);
        !            75: 
        !            76: /* else we'll have to call a shell ... */
        !            77: 
        !            78:        for (i=0; environ[i] && strncmp(environ[i], "ARGV=", 5); i++)
        !            79:        {       strcpy(ep, environ[i]);
        !            80:                ep+=strlen(ep)+1;
        !            81:        }
        !            82:        if (environ[i])
        !            83:        {
        !            84:                strcpy(ep, environ[i]); ep+=strlen(ep)+1;
        !            85:                strcpy(ep, o_shell); ep+=strlen(ep)+1;
        !            86:                strcpy(ep, "-c"); ep+=3;
        !            87:                strcpy(ep, cmd); ep+=strlen(ep)+1;
        !            88:        }
        !            89:        *ep='\0';
        !            90:        strcpy(line+1, "-c ");
        !            91:        strncat(line+1, cmd, 126);
        !            92:        line[0]=strlen(line+1);
        !            93:        return Pexec(0, o_shell, line, env);
        !            94: #endif
        !            95: }
        !            96: 
        !            97: /* This private function opens a pipe from a filter.  It is similar to the
        !            98:  * system() function above, and to popen(cmd, "r").
        !            99:  * sorry - i cant use cmdstate until rpclose, but get it from spawnle.
        !           100:  */
        !           101: 
        !           102: static int cmdstate;
        !           103: static char output[80];
        !           104: 
        !           105: int rpipe(cmd, in)
        !           106:        char    *cmd;   /* the filter command to use */
        !           107:        int     in;     /* the fd to use for stdin */
        !           108: {
        !           109:        int     fd, old0, old1, old2;
        !           110: 
        !           111:        /* create the file that will collect the filter's output */
        !           112:        strcpy(output, o_directory);
        !           113:        if ((fd=strlen(output)) && !strchr("/\\:", output[fd-1]))
        !           114:                output[fd++]=SLASH;
        !           115:        strcpy(output+fd, SCRATCHIN+3);
        !           116:        mktemp(output);
        !           117:        close(creat(output, 0666));
        !           118:        if ((fd=open(output, O_RDWR))==-1)
        !           119:        {
        !           120:                unlink(output);
        !           121:                return -1;
        !           122:        }
        !           123: 
        !           124:        /* save and redirect stdin, stdout, and stderr */
        !           125:        old0=dup(0);
        !           126:        old1=dup(1);
        !           127:        if (in)
        !           128:        {
        !           129:                dup2(in, 0);
        !           130:                close(in);
        !           131:        }
        !           132:        dup2(fd, 1);
        !           133: 
        !           134:        /* call command */
        !           135:        cmdstate=system(cmd);
        !           136: 
        !           137:        /* restore old std... */
        !           138:        dup2(old0, 0); close(old0);
        !           139:        dup2(old1, 1); close(old1);
        !           140: 
        !           141:        /* rewind command output */
        !           142:        lseek(fd, 0L, 0);
        !           143:        return fd;
        !           144: }
        !           145: 
        !           146: /* This function closes the pipe opened by rpipe(), and returns 0 for success */
        !           147: int rpclose(fd)
        !           148:        int     fd;
        !           149: {
        !           150:        int     status;
        !           151: 
        !           152:        close(fd);
        !           153:        unlink(output);
        !           154:        return cmdstate;
        !           155: }
        !           156: 
        !           157: #endif

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