xor_compress: use argv[0] as the program name if it exists

3 files changed, 17 insertions, 19 deletions

diff --git a/tools/xor_compress.c b/tools/xor_compress.c
index 555274a..56a74be 100644
--- a/tools/xor_compress.c
+++ b/tools/xor_compress.c
@@ -4,9 +4,7 @@
 #include <string.h>
 #include <errno.h>
 
-#define PROGRAM_NAME "xor_compress"
-
-extern int errno;
+char *program_name;
 
 size_t file_size(FILE *f) {
     if (fseek(f, 0, SEEK_END) == -1) return 0;
@@ -40,7 +38,7 @@ unsigned char *read_files(char *filenames[], int num_files, size_t *buf_size, in
         fclose(f);
         if (read_size != f_size) {
             // fread does not set errno
-            fprintf(stderr, PROGRAM_NAME ": %s: Read error\n", filename);
+            fprintf(stderr, "%s: %s: Read error\n", program_name, filename);
             *err = 1;
             return buffer;
         }
@@ -50,7 +48,7 @@ unsigned char *read_files(char *filenames[], int num_files, size_t *buf_size, in
     return buffer;
 
 failure:
-    fprintf(stderr, PROGRAM_NAME ": %s: %s\n", filename, strerror(errno));
+    fprintf(stderr, "%s: %s: %s\n", program_name, filename, strerror(errno));
     *err = errno;
     return buffer;
 }
@@ -58,7 +56,7 @@ failure:
 int write_compressed(const char *filename, unsigned char *data, size_t n, int *err) {
     FILE *f = fopen(filename, "wb");
     if (!f) {
-        fprintf(stderr, PROGRAM_NAME ": %s: %s\n", filename, strerror(errno));
+        fprintf(stderr, "%s: %s: %s\n", program_name, filename, strerror(errno));
         *err = errno;
         return 0;
     }
@@ -98,6 +96,8 @@ int write_compressed(const char *filename, unsigned char *data, size_t n, int *e
 }
 
 int main(int argc, char *argv[]) {
+    program_name = argc ? argv[0] : "xor_compress";
+
     bool verbose = argc > 1 && !strcmp(argv[1], "-v");
     if (verbose) {
         argv++;
@@ -105,7 +105,7 @@ int main(int argc, char *argv[]) {
     }
 
     if (argc < 3) {
-        fputs("Usage: " PROGRAM_NAME " [-v] file... files.xor\n", stderr);
+        fprintf(stderr, "Usage: %s [-v] file... files.xor\n", program_name);
         exit(1);
     }
     argv++;
@@ -119,7 +119,7 @@ int main(int argc, char *argv[]) {
     if (!err) {
         int runs = write_compressed(out_filename, data, data_size, &err);
         if (!err && verbose) {
-            printf(PROGRAM_NAME ": %s: ld bc, $%x\n", out_filename, runs);
+            printf("%s: %s: ld bc, $%x\n", program_name, out_filename, runs);
         }
     }
     free(data);
diff --git a/tools/xor_compress.py b/tools/xor_compress.py
index 42d091f..ab39627 100644
--- a/tools/xor_compress.py
+++ b/tools/xor_compress.py
@@ -2,16 +2,14 @@
 
 import sys
 
-PROGRAM_NAME = "xor_compress.py"
-
-sys.argv.pop(0)
+program_name = sys.argv.pop(0) if sys.argv else "xor_compress.py"
 
 verbose = sys.argv and sys.argv[0] == '-v'
 if verbose:
     sys.argv.pop(0)
 
 if len(sys.argv) < 2:
-    print('Usage: %s [-v] file... files.xor' % PROGRAM_NAME, file=sys.stderr)
+    print('Usage: %s [-v] file... files.xor' % program_name, file=sys.stderr)
     exit(1)
 
 out_filename = sys.argv.pop()
@@ -61,4 +59,4 @@ with open(out_filename, 'wb') as f:
     f.write(output)
 
 if verbose:
-    print('%s: %s: ld bc, $%x' % (PROGRAM_NAME, out_filename, runs))
+    print('%s: %s: ld bc, $%x' % (program_name, out_filename, runs))
diff --git a/tools/xor_compress.rs b/tools/xor_compress.rs
index c9c47e7..20fe8d1 100644
--- a/tools/xor_compress.rs
+++ b/tools/xor_compress.rs
@@ -3,8 +3,6 @@ use std::process::exit;
 use std::fs::{File, write};
 use std::io::{Read, Error};
 
-const PROGRAM_NAME: &str = "xor-compress";
-
 fn compress_files<'a>(in_filenames: &'a [String], out_filename: &'a String) -> Result<u32, (&'a String, Error)> {
     let mut data = Vec::new();
     for filename in in_filenames {
@@ -63,7 +61,9 @@ fn compress_files<'a>(in_filenames: &'a [String], out_filename: &'a String) -> R
 }
 
 fn main() {
-    let mut argv: Vec<String> = args().skip(1).collect();
+    let mut argv_iter = args();
+    let program_name = argv_iter.next().expect("xor-compress");
+    let mut argv: Vec<String> = argv_iter.collect();
 
     let verbose = !argv.is_empty() && argv[0] == "-v";
     if verbose {
@@ -71,17 +71,17 @@ fn main() {
     }
 
     if argv.len() < 2 {
-        eprintln!("Usage: {} [-v] file... files.xor", PROGRAM_NAME);
+        eprintln!("Usage: {} [-v] file... files.xor", program_name);
         exit(1);
     }
 
     let out_filename = argv.pop().unwrap();
     match compress_files(&argv[..], &out_filename) {
         Ok(runs) => if verbose {
-            println!("{}: {}: ld bc, ${:x}", PROGRAM_NAME, out_filename, runs);
+            println!("{}: {}: ld bc, ${:x}", program_name, out_filename, runs);
         },
         Err((filename, err)) => {
-            eprintln!("{}: {}: {}", PROGRAM_NAME, filename, err);
+            eprintln!("{}: {}: {}", program_name, filename, err);
             exit(err.raw_os_error().unwrap_or(1));
         }
     }