Often a command wants to be run in a shell with stdout placed in a
string. This API mimics that of stdio's popen, running the given
command (not argv array) with "/bin/sh -c" then appending the output
from stdout to the buf argument.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/lib/subcmd/Makefile | 32 +++++++++++++++++++++++++++++---
tools/lib/subcmd/run-command.c | 30 ++++++++++++++++++++++++++++++
tools/lib/subcmd/run-command.h | 14 ++++++++++++++
3 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile
index b87213263a5e..23174d013519 100644
--- a/tools/lib/subcmd/Makefile
+++ b/tools/lib/subcmd/Makefile
@@ -13,6 +13,7 @@ CC ?= $(CROSS_COMPILE)gcc
LD ?= $(CROSS_COMPILE)ld
AR ?= $(CROSS_COMPILE)ar
+MKDIR = mkdir
RM = rm -f
MAKEFLAGS += --no-print-directory
@@ -55,6 +56,17 @@ CFLAGS += -I$(srctree)/tools/include/
CFLAGS += $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
+LIBAPI_DIR = $(srctree)/tools/lib/api/
+ifneq ($(OUTPUT),)
+ LIBAPI_OUTPUT = $(abspath $(OUTPUT))/libapi
+else
+ LIBAPI_OUTPUT = $(CURDIR)/libapi
+endif
+LIBAPI_DESTDIR = $(LIBAPI_OUTPUT)
+LIBAPI_INCLUDE = $(LIBAPI_DESTDIR)/include
+LIBAPI = $(LIBAPI_OUTPUT)/libapi.a
+CFLAGS += -I$(LIBAPI_OUTPUT)/include
+
SUBCMD_IN := $(OUTPUT)libsubcmd-in.o
ifeq ($(LP64), 1)
@@ -76,7 +88,9 @@ include $(srctree)/tools/build/Makefile.include
all: fixdep $(LIBFILE)
-$(SUBCMD_IN): FORCE
+prepare: $(LIBAPI)
+
+$(SUBCMD_IN): FORCE prepare
@$(MAKE) $(build)=libsubcmd
$(LIBFILE): $(SUBCMD_IN)
@@ -113,10 +127,22 @@ install_headers: $(INSTALL_HDRS)
install: install_lib install_headers
-clean:
+$(LIBAPI_OUTPUT):
+ $(Q)$(MKDIR) -p $@
+
+$(LIBAPI): FORCE | $(LIBAPI_OUTPUT)
+ $(Q)$(MAKE) -C $(LIBAPI_DIR) O=$(LIBAPI_OUTPUT) \
+ DESTDIR=$(LIBAPI_DESTDIR) prefix= \
+ $@ install_headers
+
+$(LIBAPI)-clean:
+ $(call QUIET_CLEAN, libapi)
+ $(Q)$(RM) -r -- $(LIBAPI_OUTPUT)
+
+clean: $(LIBAPI)-clean
$(call QUIET_CLEAN, libsubcmd) $(RM) $(LIBFILE); \
find $(or $(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM)
FORCE:
-.PHONY: clean FORCE
+.PHONY: clean FORCE prepare
diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c
index 5cdac2162532..e90b285b6720 100644
--- a/tools/lib/subcmd/run-command.c
+++ b/tools/lib/subcmd/run-command.c
@@ -7,6 +7,7 @@
#include <linux/string.h>
#include <errno.h>
#include <sys/wait.h>
+#include <api/strbuf.h>
#include "subcmd-util.h"
#include "run-command.h"
#include "exec-cmd.h"
@@ -227,3 +228,32 @@ int run_command_v_opt(const char **argv, int opt)
prepare_run_command_v_opt(&cmd, argv, opt);
return run_command(&cmd);
}
+
+int run_command_strbuf(const char *cmd, struct strbuf *buf)
+{
+ const char *argv[4] = {
+ "/bin/sh",
+ "-c",
+ cmd,
+ NULL
+ };
+ struct child_process child = {
+ .argv = argv,
+ .out = -1,
+ };
+ int err;
+ ssize_t read_sz;
+
+ err = start_command(&child);
+ if (err)
+ return err;
+
+ read_sz = strbuf_read(buf, child.out, 0);
+
+ err = finish_command(&child);
+ close(child.out);
+ if (read_sz < 0)
+ return (int)read_sz;
+
+ return err;
+}
diff --git a/tools/lib/subcmd/run-command.h b/tools/lib/subcmd/run-command.h
index 17d969c6add3..1f7a2af9248c 100644
--- a/tools/lib/subcmd/run-command.h
+++ b/tools/lib/subcmd/run-command.h
@@ -58,4 +58,18 @@ int run_command(struct child_process *);
#define RUN_COMMAND_STDOUT_TO_STDERR 4
int run_command_v_opt(const char **argv, int opt);
+struct strbuf;
+/**
+ * run_command_strbuf() - Run cmd using /bin/sh and place stdout in strbuf.
+ * @cmd: The command to run by "/bin/sh -c".
+ * @buf: The strbuf appended to by reading stdout.
+ *
+ * Similar to popen with fread, run the given command reading the stdout output
+ * to buf. As with popen, stderr output goes to the current processes stderr but
+ * may be redirected in cmd by using "2>&1".
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int run_command_strbuf(const char *cmd, struct strbuf *buf);
+
#endif /* __SUBCMD_RUN_COMMAND_H */
--
2.39.0.314.g84b9a713c41-goog
