Add -i option to sed, to edit files in-place.

1 files changed, 54 insertions, 7 deletions

diff --git a/editors/sed.c b/editors/sed.c
index 5832e99a9..a7c99a16b 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -111,7 +111,10 @@ typedef struct sed_cmd_s {
 
 /* globals */
 /* options */
-static int be_quiet = 0;
+static int be_quiet = 0, in_place=0;
+FILE *nonstdout;
+char *outname;
+
 
 static const char bad_format_in_subst[] =
         "bad format in substitution expression";
@@ -168,6 +171,13 @@ static void free_and_close_stuff(void)
 }
 #endif
 
+/* If something bad happens during -i operation, delete temp file */
+
+static void cleanup_outname(void)
+{
+  if(outname) unlink(outname);
+}
+
 /* strdup, replacing "\n" with '\n', and "\delimiter" with 'delimiter' */
 
 static void parse_escapes(char *dest, const char *string, int len, char from, char to)
@@ -690,7 +700,7 @@ static void flush_append(void)
 {
         /* Output appended lines. */
         while(append_head) {
-                puts(append_head->string);
+                fprintf(nonstdout,"%s\n",append_head->string);
                 append_tail=append_head->next;
                 free(append_head->string);
                 free(append_head);
@@ -728,12 +738,17 @@ static int puts_maybe_newline(char *s, FILE *file, int missing_newline, int no_n
         fputs(s,file);
         if(!no_newline) fputc('\n',file);
 
+    if(ferror(file)) {
+                fprintf(stderr,"Write failed.\n");
+                exit(4);  /* It's what gnu sed exits with... */
+        }
+
         return no_newline;
 }
 
-#define sed_puts(s,n) missing_newline=puts_maybe_newline(s,stdout,missing_newline,n)
+#define sed_puts(s,n) missing_newline=puts_maybe_newline(s,nonstdout,missing_newline,n)
 
-static void process_file(FILE * file)
+static void process_file(FILE *file)
 {
         char *pattern_space, *next_line, *hold_space=NULL;
         static int linenum = 0, missing_newline=0;
@@ -819,7 +834,7 @@ restart:
 
                                         /* Print line number */
                                         case '=':
-                                                printf("%d\n", linenum);
+                                                fprintf(nonstdout,"%d\n", linenum);
                                                 break;
 
                                         /* Write the current pattern space up to the first newline */
@@ -1091,8 +1106,12 @@ extern int sed_main(int argc, char **argv)
 #endif
 
         /* do normal option parsing */
-        while ((opt = getopt(argc, argv, "ne:f:")) > 0) {
+        while ((opt = getopt(argc, argv, "ine:f:")) > 0) {
                 switch (opt) {
+                case 'i':
+                        in_place++;
+                        atexit(cleanup_outname);
+                        break;
                 case 'n':
                         be_quiet++;
                         break;
@@ -1131,23 +1150,51 @@ extern int sed_main(int argc, char **argv)
         /* Flush any unfinished commands. */
         add_cmd("");
 
+        /* By default, we write to stdout */
+        nonstdout=stdout;
+
         /* argv[(optind)..(argc-1)] should be names of file to process. If no
          * files were specified or '-' was specified, take input from stdin.
          * Otherwise, we process all the files specified. */
         if (argv[optind] == NULL) {
+                if(in_place) {
+                        fprintf(stderr,"sed: Filename required for -i\n");
+                        exit(1);
+                }
                 process_file(stdin);
         } else {
                 int i;
                 FILE *file;
 
                 for (i = optind; i < argc; i++) {
-                        if(!strcmp(argv[i], "-")) {
+                        if(!strcmp(argv[i], "-") && !in_place) {
                                 process_file(stdin);
                         } else {
                                 file = bb_wfopen(argv[i], "r");
                                 if (file) {
+                                        if(in_place) {
+                                                struct stat statbuf;
+                                                outname=bb_xstrndup(argv[i],strlen(argv[i])+6);
+                                                strcat(outname,"XXXXXX");
+                                                /* Set permissions of output file */
+                                                fstat(fileno(file),&statbuf);
+                                                mkstemp(outname);
+                                                nonstdout=bb_wfopen(outname,"w");
+                                                /* Set permissions of output file */
+                                                fstat(fileno(file),&statbuf);
+                                                fchmod(fileno(file),statbuf.st_mode);
+                                                atexit(cleanup_outname);
+                                        }
                                         process_file(file);
                                         fclose(file);
+                                        if(in_place) {
+                                                fclose(nonstdout);
+                                                nonstdout=stdout;
+                                                unlink(argv[i]);
+                                                rename(outname,argv[i]);
+                                                free(outname);
+                                                outname=0;
+                                        }
                                 } else {
                                         status = EXIT_FAILURE;
                                 }