Minor cleanups after merge.

docs/ACKNOWLEDGEMENTS.md

@@ -91,5 +91,6 @@ is acknowledged and greatly appreciated:
  * [gustav-b](https://codeberg.org/gustav-b) - suggested percentage formatting correction ([#80](https://codeberg.org/a-j-wood/pv/issues/80))
  * [Thomas Bertels](https://codeberg.org/tbertels) - updated French translations ([#83](https://codeberg.org/a-j-wood/pv/pulls/83))
  * [kevinruddy](https://codeberg.org/kevinruddy) - added decimal units option ([#85](https://codeberg.org/a-j-wood/pv/pulls/85))
+ * [xmort](https://codeberg.org/xmort) - added "`--output`" option ([#90](https://codeberg.org/a-j-wood/pv/pulls/90))
 
 ---

docs/NEWS.md

@@ -1,3 +1,7 @@
+### NOT YET RELEASED
+
+ * feature: new "`--output`" option to write to a file instead of standard output (pull request [#90](https://codeberg.org/a-j-wood/pv/pulls/90)) supplied by [xmort](https://codeberg.org/xmort)
+
 ### 1.8.9 - 21 April 2024
 
  * feature: new "`--si`" option to display and interpret size suffixes in multiples of 1000 rather than 1024 (pull request [#85](https://codeberg.org/a-j-wood/pv/pulls/85)) supplied by [kevinruddy](https://codeberg.org/kevinruddy)

docs/pv.1

@@ -347,7 +347,8 @@ invocations in a single, long, pipeline.
 .BI \-o\  FILE \fR,\ \fB\-\-output\  FILE
 Write data to
 .I FILE
-rather than stdout.
+rather than standard output.  If the file already exists, it will be
+overwritten from the start, but not truncated.
 .TP
 .BI \-L\  RATE \fR,\ \fB\-\-rate-limit\  RATE
 Limit the transfer to a maximum of

docs/pv.1.md

@@ -257,6 +257,12 @@ that are explicitly switched on will be shown.
 
 # DATA TRANSFER MODIFIERS
 
+**-o FILE, \--output FILE**
+
+:   Write data to *FILE* rather than standard output. If the file
+    already exists, it will be overwritten from the start, but not
+    truncated.
+
 **-L RATE, \--rate-limit RATE**
 
 :   Limit the transfer to a maximum of *RATE* bytes per second. A suffix

src/main/main.c

@@ -12,7 +12,7 @@
 #include "pv.h"
 
 /* We do not set this because it breaks "dd" - see below. */
-/* #undef MAKE_STDOUT_NONBLOCKING */
+/* #undef MAKE_OUTPUT_NONBLOCKING */
 
 #include <stdio.h>
 #include <string.h>
@@ -306,23 +306,32 @@ int main(int argc, char **argv)
 	if (NULL == opts->output || 0 == strcmp(opts->output, "-")) {
 		pv_state_output_set(state, STDOUT_FILENO, "(stdout)");
 	} else {
-		int fd = open(opts->output, O_WRONLY | O_CREAT);
+		int fd = open(opts->output, O_WRONLY | O_CREAT, 0600);	/* flawfinder: ignore */
+		/*
+		 * flawfinder rationale: the output filename has been
+		 * explicitly provided, and in many cases the operator will
+		 * want to write to device files and other special
+		 * destinations, so there is no sense-checking we can do to
+		 * make this safer.
+		 */
 		if (fd < 0) {
 			fprintf(stderr, "%s: %s: %s\n", opts->program_name, opts->output, strerror(errno));
-			return 1;
+			pv_state_free(state);
+			opts_free(opts);
+			return 2;
 		}
 		pv_state_output_set(state, fd, opts->output);
 	}
 
-#ifdef MAKE_STDOUT_NONBLOCKING
+#ifdef MAKE_OUTPUT_NONBLOCKING
 	/*
-	 * Try and make standard output use non-blocking I/O.
+	 * Try and make the output use non-blocking I/O.
 	 *
 	 * Note that this can cause problems with (broken) applications
-	 * such as dd.
+	 * such as dd when used in a pipeline.
 	 */
-	fcntl(STDOUT_FILENO, F_SETFL, O_NONBLOCK | fcntl(STDOUT_FILENO, F_GETFL));
-#endif				/* MAKE_STDOUT_NONBLOCKING */
+	fcntl(state->control.output_fd, F_SETFL, O_NONBLOCK | fcntl(state->control.output_fd, F_GETFL));
+#endif				/* MAKE_OUTPUT_NONBLOCKING */
 
 	/* Initialise the signal handling. */
 	pv_sig_init(state);

src/pv/file.c

@@ -144,7 +144,8 @@ static off_t pv_calc_total_bytes(pvstate_t state)
 				total = end_position;
 			}
 			if (lseek(state->control.output_fd, 0, SEEK_SET) != 0) {
-				pv_error(state, "%s: %s: %s", state->control.output_name,
+				pv_error(state, "%s: %s: %s",
+					 NULL == state->control.output_name ? "(null)" : state->control.output_name,
 					 _("failed to seek to start of output"), strerror(errno));
 				state->status.exit_status |= 2;
 			}

src/pv/state.c

@@ -107,6 +107,26 @@ void pv_state_free(pvstate_t state)
 	if (0 == state)
 		return;
 
+	/*
+	 * Close the output file first, so we can report any errors while we
+	 * still know the program name and output filename.
+	 */
+	if (state->control.output_fd >= 0) {
+		if (STDOUT_FILENO != state->control.output_fd) {
+			if (close(state->control.output_fd) < 0) {
+				fprintf(stderr, "%s: %s: %s\n", state->status.program_name,
+					NULL == state->control.output_name ? "(null)" : state->control.output_name,
+					strerror(errno));
+			}
+		}
+		state->control.output_fd = -1;
+	}
+
+	if (NULL != state->control.output_name) {
+		free(state->control.output_name);
+		state->control.output_name = NULL;
+	}
+
 	if (NULL != state->status.program_name)
 		free(state->status.program_name);
 	state->status.program_name = NULL;
@@ -125,23 +145,6 @@ void pv_state_free(pvstate_t state)
 		state->control.format_string = NULL;
 	}
 
-	if (NULL != state->control.output_name) {
-		free(state->control.output_name);
-		state->control.output_name = NULL;
-	}
-
-	if (NULL != state->control.output_name) {
-		free(state->control.output_name);
-		state->control.output_name = NULL;
-	}
-
-	if (state->control.output_fd >= 0) {
-		if (STDOUT_FILENO != state->control.output_fd) {
-			close(state->control.output_fd);
-		}
-		state->control.output_fd = -1;
-	}
-
 	/*@-keeptrans@ */
 	if (NULL != state->transfer.transfer_buffer)
 		free(state->transfer.transfer_buffer);
@@ -367,12 +370,21 @@ void pv_state_watch_fd_set(pvstate_t state, int val)
 
 void pv_state_output_set(pvstate_t state, int fd, const char *name)
 {
+	/*
+	 * Close any previous output file first, so we can report any errors
+	 * before we store the new output filename.
+	 */
+	if (state->control.output_fd >= 0 && state->control.output_fd != STDOUT_FILENO) {
+		if (close(state->control.output_fd) < 0) {
+			fprintf(stderr, "%s: %s: %s\n", state->status.program_name,
+				NULL == state->control.output_name ? "(null)" : state->control.output_name,
+				strerror(errno));
+		}
+	}
 	if (NULL != state->control.output_name)
 		free(state->control.output_name);
-	if (state->control.output_fd >= 0 && state->control.output_fd != STDOUT_FILENO)
-		close(state->control.output_fd);
 	state->control.output_fd = fd;
-	state->control.output_name = strdup(name);
+	state->control.output_name = pv_strdup(name);
 }
 
 void pv_state_average_rate_window_set(pvstate_t state, unsigned int val)

src/pv/transfer.c

@@ -931,7 +931,9 @@ ssize_t pv_transfer(pvstate_t state, int fd, bool *eof_in, bool *eof_out, off_t
 			if (0 != fcntl(state->control.output_fd, F_SETFL,
 				       (state->control.direct_io ? O_DIRECT : 0) |
 				       fcntl(state->control.output_fd, F_GETFL))) {
-				debug("%s: %s: %s", state->control.output_name, "fcntl", strerror(errno));
+				debug("%s: %s: %s",
+				      NULL == state->control.output_name ? "(null)" : state->control.output_name,
+				      "fcntl", strerror(errno));
 			}
 		}
 		state->control.direct_io_changed = false;