Be ever so pedantic about escaping chars that the shell might not like...

1 files changed, 59 insertions, 17 deletions

diff --git a/findutils/xargs.c b/findutils/xargs.c
index 478e0ee6d..21bfb6bbe 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -29,6 +29,59 @@
 #include <getopt.h>
 #include <ctype.h>
 
+/* get_sh_safe_line_from_file() - This function reads an entire line from a text file
+ * up to a newline. It returns a malloc'ed char * which must be stored and
+ * free'ed  by the caller. */
+extern char *get_sh_safe_line_from_file(FILE *file)
+{
+        static const int GROWBY = 80; /* how large we will grow strings by */
+
+        char ch, last_ch = 0;
+        char tmp[]=" ";
+        int idx = 0;
+        char *linebuf = NULL;
+        int linebufsz = 0;
+
+        while (1) {
+                ch = fgetc(file);
+                if (ch == EOF)
+                        break;
+                
+                /* grow the line buffer as necessary */
+                while (idx > linebufsz-4)
+                        linebuf = xrealloc(linebuf, linebufsz += GROWBY);
+
+                /* Remove any extra spaces */
+                if (last_ch == ' ' && ch == ' ')
+                        continue;
+
+                /* Replace any tabs with spaces */
+                if (ch == '\t')
+                        ch=' ';
+
+                /* Escape any characters that are treated specially by /bin/sh */
+                *tmp=ch;
+                if (strpbrk(tmp, "\\~`!$^&*()=|{}[];\"'<>?#") != NULL && last_ch!='\\') {
+                        linebuf[idx++] = '\\';
+                }
+
+                linebuf[idx++] = ch;
+                last_ch=ch;
+
+                if (ch == '\n')
+                        break;
+        }
+        if (idx == 0 && last_ch!=0)
+                linebuf[idx++]=' ';
+
+        if (idx == 0)
+                return NULL;
+
+        linebuf[idx] = 0;
+        return linebuf;
+}
+
+
 
 int xargs_main(int argc, char **argv)
 {
@@ -54,7 +107,7 @@ int xargs_main(int argc, char **argv)
         }
 
         /* Store the command and arguments to be executed (from the command line) */
-        if (argc == 1) {
+        if (argc == 0) {
                 len_args_from_cmdline = 6;
                 args_from_cmdline = xmalloc(len_args_from_cmdline);
                 strcat(args_from_cmdline, "echo ");
@@ -72,6 +125,7 @@ int xargs_main(int argc, char **argv)
                         }
                         strcat(args_from_cmdline, *argv);
                         strcat(args_from_cmdline, " ");
+                        ++argv;
                 }
         }
 
@@ -79,30 +133,19 @@ int xargs_main(int argc, char **argv)
         len_cmd_to_be_executed=10;
         cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
         strcpy(cmd_to_be_executed, args_from_cmdline);
-        strcat(cmd_to_be_executed, " \"");
 
         /* Now, read in one line at a time from stdin, and run command+args on it */
-        in_from_stdin = get_line_from_file(stdin);
+        in_from_stdin = get_sh_safe_line_from_file(stdin);
         for (;in_from_stdin!=NULL;) {
                 char *tmp;
                 opt = strlen(in_from_stdin);
                 len = opt + len_args_from_cmdline;
                 len_cmd_to_be_executed+=len+3;
                 cmd_to_be_executed=xrealloc(cmd_to_be_executed, len_cmd_to_be_executed);
-                        
+
                 /* Strip out the final \n */
                 in_from_stdin[opt-1]=' ';
-                
-                /* Replace any tabs with spaces */
-                while( (tmp = strchr(in_from_stdin, '\t')) != NULL )
-                        *tmp=' ';
-
-                /* Strip out any extra intra-word spaces */
-                while( (tmp = strstr(in_from_stdin, "  ")) != NULL ) {
-                        opt = strlen(in_from_stdin);
-                        memmove(tmp, tmp+1, opt-(tmp-in_from_stdin));
-                }
-
+                        
                 /* trim trailing whitespace */
                 opt = strlen(in_from_stdin) - 1;
                 while (isspace(in_from_stdin[opt]))
@@ -118,10 +161,9 @@ int xargs_main(int argc, char **argv)
                 strcat(cmd_to_be_executed, " ");
         
                 free(in_from_stdin);
-                in_from_stdin = get_line_from_file(stdin);
+                in_from_stdin = get_sh_safe_line_from_file(stdin);
         }
 
-        strcat(cmd_to_be_executed, "\"");
         if (traceflag==1)
                 fputs(cmd_to_be_executed, stderr);