diff --git a/utils/echo.cpp b/utils/echo.cpp
index a077d3d2..4ce3854f 100644
--- a/utils/echo.cpp
+++ b/utils/echo.cpp
@@ -1,6 +1,6 @@
/*******************************************************************************
- Copyright(C) Jonas 'Sortie' Termansen 2011.
+ Copyright(C) Jonas 'Sortie' Termansen 2011, 2013.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
@@ -16,37 +16,197 @@
this program. If not, see .
echo.cpp
- Display a line of text.
+ Write arguments to standard output.
*******************************************************************************/
+#include
+#include
#include
#include
#include
-#include
+#include
+
+#if !defined(VERSIONSTR)
+#define VERSIONSTR "unknown version"
+#endif
+
+static void help(FILE* fp, const char* argv0)
+{
+ fprintf(fp, "Usage: %s [SHORT-OPTION]... [STRING]...\n", argv0);
+ fprintf(fp, " or: %s [LONG-OPTION]\n", argv0);
+ fprintf(fp, "Echo the STRING(s) to standard output.\n");
+ fprintf(fp, "\n");
+ fprintf(fp, " -n do not output the trailing newline\n");
+ fprintf(fp, " -e enable interpretation of backslash escapes\n");
+ fprintf(fp, " -E disable interpretation of backslash escapes (default)\n");
+ fprintf(fp, " --help display this help and exit\n");
+ fprintf(fp, " --version output version information and exit\n");
+ fprintf(fp, "\n");
+ fprintf(fp, "If -e is in effect, the following sequences are recognized:\n");
+ fprintf(fp, "\n");
+ fprintf(fp, " \\\\ backslash\n");
+ fprintf(fp, " \\a alert (BEL)\n");
+ fprintf(fp, " \\b backspace\n");
+ fprintf(fp, " \\c produce no further output\n");
+ fprintf(fp, " \\e escape\n");
+ fprintf(fp, " \\f form feed\n");
+ fprintf(fp, " \\n new line\n");
+ fprintf(fp, " \\r carriage return\n");
+ fprintf(fp, " \\t horizontal tab\n");
+ fprintf(fp, " \\v vertical tab\n");
+ fprintf(fp, " \\0NNN byte with octal value NNN (1 to 3 digits)\n");
+ fprintf(fp, " \\xHH byte with hexadecimal value HH (1 to 2 digits)\n");
+ fprintf(fp, "\n");
+}
+
+static void version(FILE* fp, const char* argv0)
+{
+ fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
+ fprintf(fp, "License GPLv3+: GNU GPL version 3 or later .\n");
+ fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
+ fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
+}
+
+static bool is_allowed_short_argument(const char* argument)
+{
+ if ( argument[0] != '-' )
+ return false;
+ if ( !argument[1] )
+ return false;
+ for ( size_t i = 1; argument[i]; i++ )
+ {
+ switch ( argument[i] )
+ {
+ case 'e': break;
+ case 'E': break;
+ case 'n': break;
+ default: return false;
+ }
+ }
+ return true;
+}
int main(int argc, char* argv[])
{
- int startfrom = 1;
- bool trailingnewline = true;
- if ( 1 < argc && strcmp(argv[1], "-n") == 0 )
+ bool newline = true;
+ bool escape_sequences = false;
+
+ if ( 2 == argc && !strcmp(argv[1], "--help") )
+ help(stdout, argv[0]), exit(0);
+ if ( 2 == argc && !strcmp(argv[1], "--version") )
+ version(stdout, argv[0]), exit(0);
+
+ for ( int i = 1; i < argc; i++ )
{
- trailingnewline = false;
- startfrom = 2;
+ const char* arg = argv[i];
+ if ( !is_allowed_short_argument(arg) )
+ break;
+ argv[i] = NULL;
+ for ( size_t n = 1; arg[n]; n++ )
+ {
+ switch ( arg[n] )
+ {
+ case 'e': escape_sequences = true; break;
+ case 'E': escape_sequences = false; break;
+ case 'n': newline = false; break;
+ default: break;
+ }
+ }
}
const char* prefix = "";
- for ( int i = startfrom; i < argc; i++ )
+ for ( int i = 1; i < argc; i++ )
{
- if ( printf("%s%s", prefix, argv[i]) < 0 )
+ const char* arg = argv[i];
+ if ( !arg )
+ continue;
+ if ( !escape_sequences )
{
- perror("");
- exit(1);
+ if ( printf("%s%s", prefix, arg) < 0 )
+ error(1, errno, "");
+ }
+ else
+ {
+ if ( printf("%s", prefix) < 0 )
+ error(1, errno, "");
+ bool escaped = false;
+ for ( size_t i = 0; arg[i]; i++ )
+ {
+ char c = arg[i];
+ if ( escaped && (escaped = false, true) )
+ {
+ if ( c == '0' && (i++, true) )
+ {
+ int value = 0;
+ if ( '0' <= arg[i] && arg[i] <= '7' )
+ value = value * 8 + arg[i] - '0', i++;
+ if ( '0' <= arg[i] && arg[i] <= '7' )
+ value = value * 8 + arg[i] - '0', i++;
+ if ( '0' <= arg[i] && arg[i] <= '7' )
+ value = value * 8 + arg[i] - '0', i++;
+ if ( 255 < value )
+ value &= 255;
+ if ( putchar(value) == EOF )
+ error(1, errno, "");
+ i--;
+ continue;
+ }
+ if ( c == 'x' && (i++, true) )
+ {
+ int value = 0;
+ if ( '0' <= arg[i] && arg[i] <= '7' )
+ value = value * 16 + arg[i] - '0', i++;
+ else if ( 'a' <= arg[i] && arg[i] <= 'f' )
+ value = value * 16 + arg[i] - 'a' + 10, i++;
+ else if ( 'A' <= arg[i] && arg[i] <= 'F' )
+ value = value * 16 + arg[i] - 'A' + 10, i++;
+ if ( '0' <= arg[i] && arg[i] <= '7' )
+ value = value * 16 + arg[i] - '0', i++;
+ else if ( 'a' <= arg[i] && arg[i] <= 'f' )
+ value = value * 16 + arg[i] - 'a' + 10, i++;
+ else if ( 'A' <= arg[i] && arg[i] <= 'F' )
+ value = value * 16 + arg[i] - 'A' + 10, i++;
+ if ( putchar(value) == EOF )
+ error(1, errno, "");
+ i--;
+ continue;
+ }
+ switch ( c )
+ {
+ case '\\': c = '\\'; break;
+ case 'a': c = '\a'; break;
+ case 'b': c = '\b'; break;
+ case 'c': goto no_futher_output;
+ case 'e': c = '\e'; break;
+ case 'f': c = '\f'; break;
+ case 'n': c = '\n'; break;
+ case 'r': c = '\r'; break;
+ case 't': c = '\t'; break;
+ case 'v': c = '\v'; break;
+ default: break;
+ }
+ }
+ else if ( c == '\\' )
+ {
+ escaped = true;
+ continue;
+ }
+ if ( putchar((unsigned char) c) == EOF )
+ error(1, errno, "");
+ }
+ if ( escaped && putchar('\\') == EOF )
+ error(1, errno, "");
}
prefix = " ";
}
- if ( trailingnewline ) { printf("\n"); }
+ if ( newline && printf("\n") < 0 )
+ error(1, errno, "");
+
+no_futher_output:
+ if ( fflush(stdout) != 0 || fsync(1) != 0 )
+ error(1, errno, "");
return 0;
}