coreutils

link: Add POSIX link

Diffstat

4 files changed, 126 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a5bf1e..3775099 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,7 @@ ADD_EXECUTABLE(cat      ${CMAKE_SOURCE_DIR}/src/cat.c)
 ADD_EXECUTABLE(dirname  ${CMAKE_SOURCE_DIR}/src/dirname.c)
 ADD_EXECUTABLE(echo     ${CMAKE_SOURCE_DIR}/src/echo.c)
 ADD_EXECUTABLE(false    ${CMAKE_SOURCE_DIR}/src/false.c)
+ADD_EXECUTABLE(link     ${CMAKE_SOURCE_DIR}/src/link.c)
 ADD_EXECUTABLE(tee      ${CMAKE_SOURCE_DIR}/src/tee.c)
 ADD_EXECUTABLE(true     ${CMAKE_SOURCE_DIR}/src/true.c)
 ADD_EXECUTABLE(yes      ${CMAKE_SOURCE_DIR}/src/yes.c)
diff --git a/README.md b/README.md
index 14790ac..648724d 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ commonly found on UNIX-like systems.
 | dirname          | Return the directory portion of a path   | POSIX    |
 | echo             | Write arguments to standard output       | POSIX    |
 | false            | Return false value                       | POSIX    |
+| link             | Create a link to a file                  | POSIX    |
 | tee              | Duplicate standard input                 | POSIX    |
 | true             | Return true value                        | POSIX    |
 | yes              | Output a string repeatedly               |          |
diff --git a/man/link.1 b/man/link.1
new file mode 100644
index 0000000..fc52358
--- /dev/null
+++ b/man/link.1
@@ -0,0 +1,40 @@
+.TH LINK 1 2020-06-26 "OMKOV coreutils" "General Commands Manual"
+.SH NAME
+link \(em create a link to a file
+.SH SYNOPSYS
+\fBlink\fR \fIfile1\fR \fIfile2\fR
+.SH DESCRIPTION
+Create a link to \fIfile1\fR named \fIfile2\fR by calling the link function.
+.SH OPTIONS
+The following options are supported:
+.TP
+.B --help
+Display help information.
+.TP
+.B --version
+Display version information.
+.SH OPERANDS
+The following operands are supported:
+.TP
+.I file1
+A path of an existing file.
+.TP
+.I file2
+A path of a new file to be created.
+.SH EXIT STATUS
+The following exit values will be returned:
+.TP
+\ 0
+Successful completion.
+.TP
+>0
+An error occurred.
+.SH STANDARDS
+The \fIlink\fR utility is compliant with the IEEE Std 1003.2-1992 ("POSIX.2")
+specification.
+.SH COPYRIGHT
+.nf
+Copyright (C) 2020, Jakob Wakeling
+All rights reserved.
+OMKOV Permissive Licence (https://www.omkov.net/OLPE)
+.fi
diff --git a/src/link.c b/src/link.c
new file mode 100644
index 0000000..21e071a
--- /dev/null
+++ b/src/link.c
@@ -0,0 +1,84 @@
+// link.c, version 1.0.0
+// OMKOV coreutils implementation of POSIX link
+// Copyright (C) 2020, Jakob Wakeling
+// All rights reserved.
+
+/*
+OMKOV Permissive Licence, version 1.0
+
+Copyright (C) 2020, Jakob Wakeling
+All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal with
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimers.
+* Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimers in the documentation and/or
+  other materials provided with the distribution.
+* Neither the names of the copyright holders, nor the names of its contributors
+  may be used to endorse or promote products derived from this Software without
+  specific prior written permission.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT
+HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.
+*/
+
+#include "error.h"
+#include "optget.h"
+
+#include <unistd.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+static void help(void);
+static void version(void);
+
+int main(int argc, char *argv[]) {
+	lop_t lops[] = {
+		{ "help",    ARG_NUL, 256 },
+		{ "version", ARG_NUL, 257 },
+		{ NULL, 0, 0 }
+	};
+	
+	opt_t opt = OPTGET_INIT; opt.str = ""; opt.lops = lops; int o;
+	while ((o = optget(&opt, argv, 1)) != -1) switch (o) {
+	case 256: { help(); return 0; }
+	case 257: { version(); return 0; }
+	default: { return 1; }
+	}
+	
+	if (argc <= 2) { error(1, "%s: missing operand", argv[0]); }
+	
+	if (link(argv[1], argv[2])) { error(1, "%s: %s", argv[0], serrno); }
+	
+	return 0;
+}
+
+static void help(void) {
+	puts("link - create a link to a file\n");
+	puts("usage: link file1 file2\n");
+	puts("options:");
+	puts("  --help     Display help information");
+	puts("  --version  Display version information");
+	return;
+}
+
+static void version(void) {
+	puts("OMKOV coreutils link, version 1.0.0");
+	puts("Copyright (C) 2020, Jakob Wakeling");
+	puts("All rights reserved.");
+	puts("OMKOV Permissive Licence (https://www.omkov.net/OLPE)");
+	return;
+}