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/*
 * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
 * See LICENSE file for license details.
 */
#include "dwm.h"

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>

/* static functions */

static void
bad_malloc(unsigned int size)
{
	fprintf(stderr, "fatal: could not malloc() %d bytes\n",
			(int) size);
	exit(1);
}

/* extern functions */

void *
emallocz(unsigned int size)
{
	void *res = calloc(1, size);
	if(!res)
		bad_malloc(size);
	return res;
}

void
eprint(const char *errstr, ...) {
	va_list ap;
	va_start(ap, errstr);
	vfprintf(stderr, errstr, ap);
	va_end(ap);
	exit(1);
}

void
spawn(Arg *arg)
{
	char **argv = (char **)arg->argv;
	if(!argv || !argv[0])
		return;
	if(fork() == 0) {
		if(fork() == 0) {
			if(dpy)
				close(ConnectionNumber(dpy));
			setsid();
			execvp(argv[0], argv);
			fprintf(stderr, "dwm: execvp %s", argv[0]);
			perror(" failed");
		}
		exit (0);
	}
	wait(0);
}
aaaaa; background-color: #080808; } .subxS2Comment a { color:inherit; } .subxS1Comment a { color:inherit; } .subxComment a { color:inherit; } .subxH2Comment a { color:inherit; } .subxH1Comment a { color:inherit; } * { font-size:12pt; font-size: 1em; } .subxComment { color:#16bfff; } .subxS2Comment { color:#4466ff; } .LineNr { color:#444444; } .subxS1Comment { color:#2d8cff; } .SpecialChar { color: #ff0000; } .CommentedCode { color: #6c6c6c; } --> </style> <script type='text/javascript'> <!-- /* function to open any folds containing a jumped-to line before jumping to it */ function JumpToLine() { var lineNum; lineNum = window.location.hash; lineNum = lineNum.substr(1); /* strip off '#' */ if (lineNum.indexOf('L') == -1) { lineNum = 'L'+lineNum; } lineElem = document.getElementById(lineNum); /* Always jump to new location even if the line was hidden inside a fold, or * we corrected the raw number to a line ID. */ if (lineElem) { lineElem.scrollIntoView(true); } return true; } if ('onhashchange' in window) { window.onhashchange = JumpToLine; } --> </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/master/subx/examples/ex7.subx'>https://github.com/akkartik/mu/blob/master/subx/examples/ex7.subx</a> <pre id='vimCodeElement'> <span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Example showing file syscalls.</span> <span id="L2" class="LineNr"> 2 </span><span class="subxComment">#</span> <span id="L3" class="LineNr"> 3 </span><span class="subxComment"># Create a file, open it for writing, write a character to it, close it, open</span> <span id="L4" class="LineNr"> 4 </span><span class="subxComment"># it for reading, read a character from it, close it, delete it, and return</span> <span id="L5" class="LineNr"> 5 </span><span class="subxComment"># the character read.</span> <span id="L6" class="LineNr"> 6 </span><span class="subxComment">#</span> <span id="L7" class="LineNr"> 7 </span><span class="subxComment"># To run (from the subx directory):</span> <span id="L8" class="LineNr"> 8 </span><span class="subxComment"># $ subx translate examples/ex7.subx -o examples/ex7</span> <span id="L9" class="LineNr"> 9 </span><span class="subxComment"># $ subx run examples/ex7</span> <span id="L10" class="LineNr"> 10 </span><span class="subxComment"># Expected result:</span> <span id="L11" class="LineNr"> 11 </span><span class="subxComment"># $ echo $?</span> <span id="L12" class="LineNr"> 12 </span><span class="subxComment"># 97</span> <span id="L13" class="LineNr"> 13 </span> <span id="L14" class="LineNr"> 14 </span>== code <span id="L15" class="LineNr"> 15 </span><span class="subxComment"># instruction effective address register displacement immediate</span> <span id="L16" class="LineNr"> 16 </span><span class="subxS1Comment"># . op subop mod rm32 base index scale r32</span> <span id="L17" class="LineNr"> 17 </span><span class="subxS1Comment"># . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes</span> <span id="L18" class="LineNr"> 18 </span> <span id="L19" class="LineNr"> 19 </span> <span class="subxComment"># syscall(creat, Filename)</span> <span id="L20" class="LineNr"> 20 </span> bb/copy-to-EBX <span class="SpecialChar">Filename</span>/imm32 <span id="L21" class="LineNr"> 21 </span> b9/copy-to-ECX 0x180/imm32/fixed-perms <span id="L22" class="LineNr"> 22 </span> b8/copy-to-EAX 8/imm32/creat <span id="L23" class="LineNr"> 23 </span> cd/syscall 0x80/imm8 <span id="L24" class="LineNr"> 24 </span> <span id="L25" class="LineNr"> 25 </span> <span class="subxComment"># stream = syscall(open, Filename, O_WRONLY, 0) # we can't use 'fd' because it looks like a hex byte</span> <span id="L26" class="LineNr"> 26 </span> bb/copy-to-EBX <span class="SpecialChar">Filename</span>/imm32 <span id="L27" class="LineNr"> 27 </span> b9/copy-to-ECX 1/imm32/wronly <span id="L28" class="LineNr"> 28 </span> ba/copy-to-EDX 0x180/imm32/fixed-perms <span id="L29" class="LineNr"> 29 </span> b8/copy-to-EAX 5/imm32/open <span id="L30" class="LineNr"> 30 </span> cd/syscall 0x80/imm8 <span id="L31" class="LineNr"> 31 </span> <span class="subxComment"># save stream</span> <span id="L32" class="LineNr"> 32 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L33" class="LineNr"> 33 </span> 89/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 0/r32/EAX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy EAX to *EBX</span> <span id="L34" class="LineNr"> 34 </span> <span id="L35" class="LineNr"> 35 </span> <span class="subxComment"># syscall(write, Stream, &quot;a&quot;, 1)</span> <span id="L36" class="LineNr"> 36 </span> <span class="subxS1Comment"># . load stream</span> <span id="L37" class="LineNr"> 37 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L38" class="LineNr"> 38 </span> 8b/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 3/r32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy *EBX to EBX</span> <span id="L39" class="LineNr"> 39 </span> <span class="subxS1Comment"># .</span> <span id="L40" class="LineNr"> 40 </span> b9/copy-to-ECX <span class="SpecialChar">A</span>/imm32 <span id="L41" class="LineNr"> 41 </span> ba/copy-to-EDX 1/imm32/size <span id="L42" class="LineNr"> 42 </span> b8/copy-to-EAX 4/imm32/write <span id="L43" class="LineNr"> 43 </span> cd/syscall 0x80/imm8 <span id="L44" class="LineNr"> 44 </span> <span id="L45" class="LineNr"> 45 </span> <span class="subxComment"># syscall(close, Stream)</span> <span id="L46" class="LineNr"> 46 </span> <span class="subxS1Comment"># . load stream</span> <span id="L47" class="LineNr"> 47 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L48" class="LineNr"> 48 </span> 8b/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 3/r32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy *EBX to EBX</span> <span id="L49" class="LineNr"> 49 </span> <span class="subxS1Comment"># .</span> <span id="L50" class="LineNr"> 50 </span> b8/copy-to-EAX 6/imm32/close <span id="L51" class="LineNr"> 51 </span> cd/syscall 0x80/imm8 <span id="L52" class="LineNr"> 52 </span> <span id="L53" class="LineNr"> 53 </span> <span class="subxComment"># stream = syscall(open, Filename, O_RDONLY, 0)</span> <span id="L54" class="LineNr"> 54 </span> bb/copy-to-EBX <span class="SpecialChar">Filename</span>/imm32 <span id="L55" class="LineNr"> 55 </span> b9/copy-to-ECX 0/imm32/rdonly <span id="L56" class="LineNr"> 56 </span> ba/copy-to-EDX 0x180/imm32/fixed-perms <span id="L57" class="LineNr"> 57 </span> b8/copy-to-EAX 5/imm32/open <span id="L58" class="LineNr"> 58 </span> cd/syscall 0x80/imm8 <span id="L59" class="LineNr"> 59 </span> <span class="subxS1Comment"># . save Stream</span> <span id="L60" class="LineNr"> 60 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L61" class="LineNr"> 61 </span> 89/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 0/r32/EAX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy EAX to *EBX</span> <span id="L62" class="LineNr"> 62 </span> <span id="L63" class="LineNr"> 63 </span> <span class="subxComment"># syscall(read, Stream, B, 1)</span> <span id="L64" class="LineNr"> 64 </span> <span class="subxS1Comment"># . load stream</span> <span id="L65" class="LineNr"> 65 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L66" class="LineNr"> 66 </span> 8b/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 3/r32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy *EBX to EBX</span> <span id="L67" class="LineNr"> 67 </span> <span class="subxS1Comment"># .</span> <span id="L68" class="LineNr"> 68 </span> b9/copy-to-ECX <span class="SpecialChar">B</span>/imm32 <span id="L69" class="LineNr"> 69 </span> ba/copy-to-EDX 1/imm32/size <span id="L70" class="LineNr"> 70 </span> b8/copy-to-EAX 3/imm32/read <span id="L71" class="LineNr"> 71 </span> cd/syscall 0x80/imm8 <span id="L72" class="LineNr"> 72 </span> <span id="L73" class="LineNr"> 73 </span> <span class="subxComment"># syscall(close, Stream)</span> <span id="L74" class="LineNr"> 74 </span> <span class="subxS1Comment"># . load stream</span> <span id="L75" class="LineNr"> 75 </span> bb/copy-to-EBX <span class="SpecialChar">Stream</span>/imm32 <span id="L76" class="LineNr"> 76 </span> 8b/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 3/r32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy *EBX to EBX</span> <span id="L77" class="LineNr"> 77 </span> <span class="subxComment">#</span> <span id="L78" class="LineNr"> 78 </span> b8/copy-to-EAX 6/imm32/close <span id="L79" class="LineNr"> 79 </span> cd/syscall 0x80/imm8 <span id="L80" class="LineNr"> 80 </span> <span id="L81" class="LineNr"> 81 </span> <span class="subxComment"># syscall(unlink, filename)</span> <span id="L82" class="LineNr"> 82 </span> bb/copy-to-EBX <span class="SpecialChar">Filename</span>/imm32 <span id="L83" class="LineNr"> 83 </span> b8/copy-to-EAX 0xa/imm32/unlink <span id="L84" class="LineNr"> 84 </span> cd/syscall 0x80/imm8 <span id="L85" class="LineNr"> 85 </span> <span id="L86" class="LineNr"> 86 </span> <span class="subxComment"># syscall(exit, b)</span> <span id="L87" class="LineNr"> 87 </span> <span class="subxS1Comment"># . load b</span> <span id="L88" class="LineNr"> 88 </span> bb/copy-to-EBX <span class="SpecialChar">B</span>/imm32 <span id="L89" class="LineNr"> 89 </span> 8b/copy 0/mod/indirect 3/rm32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> 3/r32/EBX <span class="CommentedCode"> . </span> <span class="CommentedCode"> . </span> <span class="subxComment"># copy *EBX to EBX</span> <span id="L90" class="LineNr"> 90 </span> <span class="subxComment">#</span> <span id="L91" class="LineNr"> 91 </span> b8/copy-to-EAX 1/imm32/exit <span id="L92" class="LineNr"> 92 </span> cd/syscall 0x80/imm8 <span id="L93" class="LineNr"> 93 </span> <span id="L94" class="LineNr"> 94 </span>== data <span id="L95" class="LineNr"> 95 </span> <span id="L96" class="LineNr"> 96 </span><span class="SpecialChar">Stream</span>: <span id="L97" class="LineNr"> 97 </span> 00 00 00 00 <span id="L98" class="LineNr"> 98 </span><span class="SpecialChar">A</span>: <span id="L99" class="LineNr"> 99 </span> 61 00 00 00 <span id="L100" class="LineNr">100 </span><span class="SpecialChar">B</span>: <span id="L101" class="LineNr">101 </span> 00 00 00 00 <span id="L102" class="LineNr">102 </span><span class="SpecialChar">Filename</span>: <span id="L103" class="LineNr">103 </span> 2e 66 6f 6f 00 00 00 00 <span id="L104" class="LineNr">104 </span> <span id="L105" class="LineNr">105 </span><span class="subxS2Comment"># . . vim&#0058;nowrap:textwidth=0</span> </pre> </body> </html> <!-- vim: set foldmethod=manual : -->